Filesharing Programs 

 and 

“Technological Features to Induce Users to Share” 

A Report to the United States Patent and Trademark Office 

from the Office of International Relations

Prepared by 

Thomas D. Sydnor II 

John Knight 

Lee A. Hollaar 

v 1.1 

November, 2006 
Foreword

by Jon W. Dudas, 

Under Secretary of Commerce for Intellectual Property and Director of the United States 

Patent and Trademark Office (USPTO) 

This report originated when one of its authors showed me data on the behavior of 

filesharing programs that was being compiled for use in a law review article. Because the 

data seemed to have potentially important implications, I asked the authors to present it in 

the form of a report to USPTO. Having reviewed the resulting report, I conclude that this 

data should be made known to the public. 

This report analyzes five popular filesharing programs to determine whether they have 

contained, or do contain, “features” that can cause users of these programs to share files 

inadvertently. It concludes that these programs have deployed at least five such 

“features,” and that distributors of these programs continued to deploy such features after 

their propensity to cause users to share files inadvertently was, or should have been, 

known. It concludes that further investigation would be warranted to determine whether 

any distributors who deployed these features intended for them to trick users into sharing 

files unintentionally. 

I requested this report because I believe that it raises important questions about why 

individual users of these filesharing programs continue to infringe copyrights. This 

report also reveals that these filesharing programs threaten more than just the copyrights 

that have made the United States the world’s leading creator and exporter of expression 

and innovation: They also pose a real and documented threat to the security of personal, 

corporate, and governmental data. 

For the Federal Government, this threat became manifest during 2005, when the 

Department of Homeland Security warned all Federal Agencies that government 

employees or contractors who had installed filesharing programs on their home or work 

computers had repeatedly compromised national and military security by “sharing” files 

containing sensitive or classified data. These users probably did intend to use these 

programs to download popular music, movies, software or games. But it seems highly 

unlikely that any of them intended to compromise national or military security for the 

sake of “free music.” 

A decade ago, the idea that copyright infringement could become a threat to national 

security would have seemed implausible. Now, it is a sad reality. It is important to ask 

how and why this happened. This report attempts to provide some answers and to 

encourage further research into questions that it can raise, but not answer. 

The unanswered questions raised by this report implicate diverse competencies: Some 

might be best addressed by consumer-protection advocates or agencies, others by 

computer-science researchers. By releasing this report, I hope that USPTO will 

i 
encourage others to bring their expertise to bear on some of the questions that this report 

leaves open. Examples of such questions might include the following: 

• What is the overall prevalence of inadvertent sharing? It may be possible to 

estimate the number of users who have recursively shared “C:\” or their “My 

Documents” folder, but estimating the number of users inadvertently sharing 

downloaded files or their “My Music” folder might be much more difficult. 

• How can users of filesharing programs who do not want to upload files effectively 

avoid the sort of coerced-sharing features discussed in this report?

• What are the best options for owners of home computers who want to avoid the 

security and liability risks associated with filesharing programs? 

Finally, I reviewed this report as both a father who manages a home computer and the 

director of a Federal Agency that must protect the security of valuable electronic files and 

data. It leads me to believe that I owe a debt of thanks not only to my colleagues at the 

Department of Homeland Security, but also to two groups of persons. 

First, I would like to thank all of the computer-science researchers who have studied 

filesharing networks. They have done what scientists are supposed to do: Observed 

carefully and reported what they found—both the good and the bad. Their reports bring 

to the debate about filesharing objectivity and dispassion that has otherwise been lacking. 

I would also like to thank the researchers, reporters, agencies, private citizens, and 

information-security firms who worked for years to call attention to the persistent and 

recurring problem of inadvertent sharing. Special thanks are owned the unnamed 

Samaritan interviewed by CBS News, to the creator of the website See What You Share,

and to Dr. Howard Schmidt and the employees of Tiversa, Inc. 

ii
Table of Contents

Foreword.............................................................................................................................. i

Table of Contents...............................................................................................................iii 

I. Executive Summary.................................................................................................... 1 

II. Background................................................................................................................. 4 

A. Policy and practical considerations show the need to consider whether distributors 

may have designed filesharing programs to dupe new or vulnerable users into 

“sharing” infringing files. ....................................................................................... 4 

B. This report investigates whether popular filesharing programs contain features 

that their distributors knew or should have known could cause users to upload 

files inadvertently.................................................................................................... 8 

III. An Analysis of Potential “Technological Features To Induce Users to Share” in Five 

Popular Filesharing Programs................................................................................... 10 

A. Redistribution features can cause users to share infringing downloads 

unintentionally. ..................................................................................................... 11 

B. Search-wizard and share-folder features can cause users to infringe copyrights—

or jeopardize their own financial or personal safety—by sharing existing files 

inadvertently. ........................................................................................................ 16 

1. Share-folder features were widely deployed after their potential to cause 

inadvertent sharing was known......................................................................... 23 

2. Search-wizard features continued to be widely deployed after their potential to 

cause inadvertent sharing had been identified. ................................................. 27 

3. “Fixing” the effects of share-folder and search-wizard features—by 

perpetuating them.............................................................................................. 33 

4. Free Riding on Gnutella Revisited: The Bell Tolls?......................................... 35 

C. Recently, filesharing programs have deployed potentially misleading coercedsharing features that make it difficult, but possible, for users to stop sharing 

downloaded files. .................................................................................................. 37 

D. Next steps: Are search-wizard features poised to return?..................................... 45 

IV. Conclusions and Implications................................................................................... 46 

A. Conclusions........................................................................................................... 47 

iii
B. Implications........................................................................................................... 49 

Appendixes. ...................................................................................................................... 55 

Appendix A: The Scope of This Report. ...................................................................... 55 

Appendix B: Terms Used in This Report. .................................................................... 58 

Endnotes............................................................................................................................ 61 

iv
I. Executive Summary. 

For years, computer-science researchers, Federal Agencies, concerned private citizens, 

IT-security companies, public-interest groups, news reporters, and others have also 

reported that users of popular filesharing programs have been sharing files 

unintentionally. More recently, in MGM Studios, Inc. v. Grokster, Ltd., the Supreme 

Court found “unmistakable” and “unequivocal” evidence that distributors of two popular 

filesharing programs intended to induce users of their programs to infringe copyrights. 

The findings in Grokster suggest that persistent reports of inadvertent sharing could 

signal the effects of duping schemes, a known means of inducement. 

In a duping scheme, an entity that intends to use others as a means to achieve an illegal 

end tricks other people into inadvertently or unintentionally performing a potentially 

illegal act. In the context of filesharing, duping schemes could be particularly effective. 

Duping that caused infringing files to be shared inadvertently by young, new or 

unsophisticated users could still make millions of files available for downloading. 

Indeed, new users of filesharing programs tend to download many more files than 

established users, so duping that targeted new users could add a disproportionately large

number of files to the network. Duping schemes that targeted young or unsophisticated 

users would also ensure that attempts to enforce copyrights against those infringers who 

upload hundreds or thousands of infringing files would tend to target young or 

sympathetic users. 

This report reviews public data about the behavior of five popular filesharing programs; it 

focuses on the programs BearShare, eDonkey, KaZaA, LimeWire, and Morpheus. It 

seeks to answer two questions. First, have distributors of these filesharing programs 

deployed features that had a known or obvious propensity to trick users into uploading 

infringing files inadvertently? Second, if so, do the circumstances surrounding the 

deployment of such features suggest the need for further investigation to determine 

whether any particular distributor intended for such features to act as duping schemes—

as “technological features to induce users to share.” 

This report concludes that the distributors of these five filesharing programs have 

repeatedly deployed features that had a known propensity to trick users into uploading 

infringing files inadvertently. Distributors deployed at least five such features: 

• Redistribution features: All five programs analyzed have deployed a feature 

that will, by default, cause users of the program to upload (or “share”) all files 

that they download. These features create a counter-intuitive link between 

downloading files for personal use and distributing files to strangers, and they 

have often been implemented in ways that could make their effects less obvious to 

new users. Since 2003, lawsuits against users of filesharing programs have made 

it more important for users to understand the effects of redistribution features. 

During this period, some programs tended to disclose less information about their 

redistribution features. 

1 
• Share-folder and Search-Wizard Features: All five programs analyzed have 

deployed share-folder or search-wizard features. These features are uniquely 

dangerous: They can cause users to share inadvertently not only infringing files, 

but also sensitive personal files like tax returns, financial records, and documents 

containing private or even classified data. Published research identified these 

features as causes of inadvertent sharing by mid-2002. By mid-2003, the 

distributors of the programs analyzed here had agreed to discontinue use of these 

features, and concerned legislators had warned that their continued use would 

compromise national security because government employees using these 

programs would inadvertently share files containing sensitive or classified data. 

Nevertheless, the distributors of BearShare, eDonkey, LimeWire and Morpheus 

programs kept deploying search-wizard or share-folder features, and the 

distributors of KaZaA eliminated these features in a way that would tend to 

perpetuate inadvertent sharing previously caused by such features. By late spring 

of 2005, the Department of Homeland Security reported that government 

employees using filesharing programs had repeatedly compromised national and 

military security by “sharing” files containing sensitive or classified data. 

o Share-folder features: All five of the programs analyzed have deployed 

a feature that lets users store downloaded files in a folder other than the 

specially created folder that stores downloaded files by default—but does 

so through an interface that does not warn users that all files stored in the 

selected folder will be shared. In most cases, the sharing caused by this 

feature will be recursive: The program will share not only the files stored 

in the folder selected to store downloaded files, but also all files stored in

any of its subfolders. 

o Search-wizard features: At least three of the programs analyzed have 

deployed a feature that will search users’ hard drives and “recommend” 

that users share folders that contain certain “triggering” file types, which 

usually include document files, audio files, audiovisual files, and image 

files. Some search-wizard features activate automatically; others require 

the user to trigger them. Some are activated during a program’s 

installation-and-setup process; others are an option that a user can activate 

after the program is installed and running. Some will select identified 

folders for sharing; others “recommend,” but do not select, identified 

folders for sharing. All search-wizard features discussed will cause 

recursive sharing of identified or selected folders.

• Partial-uninstall features: At least four of the programs analyzed have deployed 

partial-uninstall features: If users uninstall one of these programs from their 

computers, the process will leave behind a file that will cause any subsequent 

installation of any version of the same program to share all folders shared by the 

“uninstalled” copy of the program. Whenever a computer is used by more than 

one person, this feature ensures that users cannot know which files and folders 

these programs will share by default.

2
• Coerced-sharing features: Four of the programs analyzed have deployed 

features that make it far more difficult for users to disable sharing of the folder 

used to store downloaded files. This folder may be the default download folder 

created by the filesharing program or an existing folder selected to store 

downloaded files through a share-folder feature. In each case, the feature can 

provide misleading feedback indicating—incorrectly—that the user has disabled 

sharing of the download folder. But in each case, an obscure mechanism appears 

to allow sophisticated users to avoid the coerced-sharing feature and stop sharing 

the download folder. 

All five of these features can cause users to share infringing files inadvertently. 

Redistribution and coerced-sharing features can cause users to share downloaded files 

inadvertently: As Grokster noted, these files are usually infringing. Share-folder, searchwizard, and partial-uninstall features can cause users to inadvertently share existing files 

on their computers: The design of these features ensures that the files shared may tend to 

include users’ collections of media files, like audio files copied from purchased CDs. 

All five programs analyzed in this report have deployed most or all of these features 

during at least some portion of the period from 2003 to 2006. In many cases, versions of 

these features actually became more aggressive after their propensity to cause inadvertent 

sharing was, or should have been, known to reasonable distributors of filesharing 

programs. For example, the distributors of BearShare, eDonkey, LimeWire and 

Morpheus began or continued to deploy poorly disclosed redistribution features, sharefolder features, search-wizard features and/or coerced-sharing features even after these 

distributors drafted a Code of Conduct that should have precluded use of any such 

features. Some distributors even responded to reports of inadvertent sharing by releasing 

new versions of their programs that seemed improved, but actually perpetuated 

inadvertent sharing caused by features previously deployed. Consequently, this report 

concludes that the totality of the circumstances surrounding the deployment of such 

features justify further investigation to determine whether particular distributors intended 

for such features to act as duping schemes. 

This report does not, however, draw conclusions about the intent of any particular 

distributor that deployed some or all of these features in its filesharing program. This 

report analyzes public data, and it is possible that nonpublic data now controlled by a 

particular distributor might show that it deployed these features mistakenly, negligently, 

or recklessly. This limitation on the scope of this report’s conclusions is a precautionary 

measure: It does not imply that a court obligated to draw conclusions about the intent of a 

particular distributor could not find that the data discussed herein provides 

“unmistakable” or “unequivocal” evidence of intent to induce copyright infringement 

within the meaning of MGM Studios, Inc. v. Grokster, 125 S. Ct. 2764 (2005). 

3
II. Background. 

A combination of two factors suggested the need for the analysis conducted in this report. 

First, on June 27, 2005, in MGM Studios, Inc. v. Grokster, Ltd., the Supreme Court of the 

United States found “unequivocal” and “unmistakable” evidence that the distributors of 

the Grokster and Morpheus filesharing programs intended to induce users of their 

programs to infringe copyrights. Duping schemes are a known means to induce others to 

perform illegal acts. 

Second, in the context of filesharing, duping schemes would, by definition, cause users of 

filesharing programs to share infringing files unintentionally. For years, researchers, 

governments, the media, and users themselves have been reporting that users of some

filesharing programs end up “sharing” files unintentionally. 

Together, these two factors suggest a need to investigate to determine whether 

distributors of filesharing programs may have used duping schemes to induce users of 

their programs to upload, or “share” infringing files unintentionally. 

A. Policy and practical considerations show the need to consider whether 

distributors may have designed filesharing programs to dupe new or 

vulnerable users into “sharing” infringing files. 

The inducement doctrine reaffirmed by the Grokster Court has long been a basis for 

imposing secondary civil liability for many forms of wrongful conduct, including 

copyright, patent, and trademark infringement. As a result, inducement cases and laws 

provide courts, rightsholders and technologists with “diagnostic tools” that can identify 

conduct that may indicate intent to induce others to break the law. 

For example, in cases involving alleged infringements of intellectual-property rights, 

courts have called inducement the civil analog of the criminal-law doctrine of aiding and 

abetting. By analogy, the two-part structure of the criminal aiding-and-abetting statute, 

(Section 2 of the United States Criminal Code), suggests that there are two means for a 

culpable entity to induce others to commit illegal acts:

• Section 2(a) Inducement (Persuasion): An entity might seek to persuade or 

encourage third parties to break the law intentionally. In the context of 

filesharing, a distributor engaged in 2(a)-type inducement might say something 

like this: “Separating the download of the data and the keys may help protect file 

sharers from lawsuits, making it more difficult for courts to say exactly which 

party is responsible for copyright infringement....”1

• Section 2(b) Inducement (Duping Schemes): An entity might also seek to dupe 

or trick third parties into breaking the law unintentionally or unwittingly. Justice 

Story’s classic example of duping involves a murderer who has food poisoned and 

delivered by a child who does not intend to harm the intended victim.

2

 In the 

context of filesharing, “duping schemes” might be executed by features in 

4
filesharing programs that trick some users into sharing files that they did not 

intend to make available to others. 

The difference between inducement-by-persuasion and duping turns on whether the 

person induced to perform a potentially illegal act intended to break the law—not on the 

use of deceit. For example, inducement-by-persuasion might well involve deceit: An 

inducer might misrepresent the odds of getting caught in order to persuade another person 

to perform an illegal act intentionally. The Grokster decision focused on evidence 

suggesting that distributors of filesharing programs encouraged users of their programs to 

infringe copyrights intentionally. The Court did not consider the possibility of duping.

After Grokster, it becomes important to consider the possibility of duping. In any 

context, duping schemes can be particularly destructive to the rule of law: 

• Duping schemes can conceal their authors: Violations of the law occur, but they 

seem to result from the mistakes or negligence of third parties. 

• Duping schemes can also endanger unwitting participants: Persons duped may 

risk civil liability or even criminal prosecution. 

• Duping schemes can also shield the culpable: A duping scheme also encourages 

culpable parties to break the law intentionally; if culpable lawbreakers are caught, 

they can avoid or minimize the consequences of their acts by posing as dupes. 

While duping schemes might seem appealing, they have remained rare in practice. 

Ordinarily, it would be unlikely that distributors of a product would have incentives to 

dupe its users into breaking the law. And even if distributors had such incentives, two 

factors would usually deter a resort to duping. 

First, consumers usually have very powerful remedies against the distributors of any 

product that causes any sort of foreseeable harm. The vast information markets that 

surround almost all popular consumer products would also be likely to detect and reveal 

any wrongdoing—and thus ensure that the remedies available to consumers would be 

brought to bear. 

Second, duping schemes could reveal themselves if they affect too many users of a 

product: If most people who use a product end up breaking the law unintentionally, it will 

become obvious that the product—and its designers—have contributed to this result. 

Duping would thus have to be calibrated to cause only a relatively small subset of users 

to break the law. Consequently, duping should occur only if some disproportionate 

benefit could be gained by tricking only a relatively small percentage of users into 

breaking the law. 

Filesharing presents an unusual context in which these practical obstacles to duping 

diminish. In practice, popular filesharing programs are used mostly to download and 

upload infringing copies of copyrighted music, movies, games, images, and software. 

For example, in Grokster, unrebutted evidence indicated that 90% of the files available 

5
on filesharing networks consisted of infringing files. Upon remand, the district court in 

Grokster found that undisputed evidence showed that “[a]lmost 97% of the files actually 

requested for downloading were infringing or highly likely to be infringing.”3

 

When almost all users of a product use it to break the law almost all of the time, the 

protections against duping provided by consumer-protection and tort laws recede. As a 

practical matter, persons who use a filesharing program to download infringing files 

cannot call their state attorney general or the Federal Trade Commission and report the 

following complaint: “I installed this program so I could download popular music 

without paying for it, but the program caused me to share the infringing files that I 

downloaded, and that got me sued.” The user who did this might well be confessing to a 

federal crime. Nor would this user be a sympathetic tort plaintiff. 

This situation also seems to deter information markets: For example, because virtually

everyone who uses a popular filesharing program appears to use it almost exclusively to 

download infringing files, a mazagine or website seeking to do a meaningful review of

filesharing programs would have to assess their relative efficacy as a means of copyright 

piracy. Perhaps for this reason, filesharing programs have become one of the most 

widely used, let least discussed and reviewed, computer programs on the market. 

Filesharing also presents the unusual case in disproportionate benefits could be gained by 

tricking only new, unsophisticated or young users of filesharing programs into sharing 

infringing files: 

• Filesharing programs are very widely used. Duping could thus cause many 

millions of files to be uploaded even if it affected only a small fraction of users. 

• New users of filesharing programs download many more files than existing 

users.4

 Duping that affected only new and unsophisticated users would thus be 

disproportionately effective at adding files to a network. 

• Many users of filesharing programs are young teenagers or preteen children.5

 

Children are the classic targets of duping. 

Taken together, these three factors suggest that schemes to dupe young, new, or 

unsophisticated users of filesharing programs into sharing infringing files unintentionally 

could help populate networks with infringing files even if they affected only a small 

percentage of users. 

An additional factor could then allow duping schemes to have a uniquely malign effect: 

Were a distributor to design its filesharing program to dupe otherwise-sympathetic users 

into “sharing” many infringing files unintentionally, the distributor responsible would not 

be the one to punish these users for their credulity. As a result, duping schemes might 

tend to vilify—not their authors—but copyright holders and copyright laws. Copyright

holders trying to deter infringement might sue the most egregious infringing users of 

filesharing programs—those few who upload hundreds or thousands of infringing files. 

6
Duping schemes could ensure that such lawsuits would actually tend to target a 

program’s youngest and most sympathetic users. 

Such a situation would raise important policy concerns. Historically, copyrights have 

generally been enforced against distributors or commercial users of protected works, but 

not against ordinary consumers. This long practice ensured that copyrighted works could 

be enjoyed by everyone—from toddlers to seniors—without the need for any detailed 

knowledge of copyright law.6

 

Filesharing became the exception to this practice because many programs were designed 

to ensure that infringing use of filesharing networks could not be halted by sending 

takedown notices to the distributors of the programs that create them, or even by suing 

those distributors into bankruptcy. After the Napster litigation, distributors were told that 

such designs could help them avoid liability: “The key here is to let go of any control you 

may have over your users—no remote kill switch, contractual termination rights or 

similar mechanisms.”7

 Thus, even if rightsholders successfully sue the distributors of 

these programs, they still confront a lose-lose-lose decision: They must either (1) try to 

deter infringement by suing the consumers who use these programs, (2) try to deter 

infringement by paying off the architects of filesharing piracy, or (3) accept ongoing, 

pervasive infringement that could eventually waive their rights to prevent unauthorized 

reproduction or distribution of their works. 

In Grokster, the Supreme Court noted, “[T]he ease of copying songs or movies using 

software like Grokster’s and Napster’s is fostering disdain for copyright protection.” 

Network architecture that forces copyright holders to waive their rights, payoff pirates, or 

sue consumers may inevitably foster further disdain for copyright protection—for the 

system of private property rights in expressive works that the Framers of the Constitution 

thought indispensable to the growth of private expression in a democratic republic. 

Indeed, after some copyright holders sued users uploading many hundreds or thousands 

of infringing files, defenders of filesharing objected that such users tend to be poor, 

unsophisticated, or children. For example, in its 2005 report, RIAA v. The People, the 

Electronic Frontier Foundation (EFF) described the users uploading many hundreds of 

infringing files as follows: “The[y] were not commercial copyright pirates. They were 

children, grandparents, [and] single mothers....” EFF then cited numerous individual 

cases involving users who were (1) unaware that sharing infringing files was illegal, (2) 

unaware that they were uploading infringing files that they had downloaded, (3) poor, (4) 

unsophisticated, (5) children or young teenagers, or (6) some or all of the above.8

The cases cited by EFF involve defendants who seem sympathetic because circumstances 

strongly suggest that they never intended to turn their home computers into online 

distribution centers for pirated goods. Another EFF lawyer condemned enforcement 

against such users as a “reign of terror” against “defenseless people” who probably did 

not intend to break the law—“any real pirate would never leave the meta-data and would 

be using someone else’s Internet access.”9

 But such condemnations just beg a more 

fundamental question: Why do children, grandparents, and poor single mothers end up 

sharing hundreds or thousands of infringing files inadvertently? 

7
Distributors of filesharing programs have also argued that the prevalence of children 

among high-volume uploaders of infringing files makes it wrong for copyright holders to 

enforce their rights. For example, one high-volume uploader of over 800 infringing 

audio files turned out to be a 12-year-old female honor student receiving public 

assistance. The distributors of the BearShare, Morpheus, and eDonkey programs 

responded to this tragic situation in the press release Peer-to-Peer Trade Group to RIAA 

Bullies: Come Out and Fight Us If You Want, But Leave the Little Guys Alone: 

[I]t’s time for the RIAA’s winged monkeys to fly back to the castle and 

leave the Munchkins alone.... 

They’re playing the Wicked Witch of the West, using $150,000-per-song 

lawsuits to frighten the little people.... 

Like the Cowardly Lion, the record industry bullies should come out and 

fight us if they want, but leave the little guys alone.10 

Such rhetoric heightens the need to investigate. Distributors of filesharing programs 

created an unprecedented, avoidable, and tragic conflict between artists and their fans. 

These distributors then denounced the enforcement lawsuits against users that their own 

choices had made nearly inevitable. But declarations of sympathy for the fate of the 

“little guys” would ring very hollow if authored by distributors deploying “features” that 

could tend to cause “the Munchkins” to become high-volume uploaders of infringing 

files. 

These policy considerations show why it is important to consider the possibility of 

duping. They are also reinforced by practical considerations. By definition, duping 

schemes would cause users of filesharing programs to “share” (or “upload”) infringing

files unintentionally. For years, an expanding set of public reports has asserted that users 

of filesharing software do “share” files unintentionally. 

Since at least 2002, such reports have come from computer-science researchers, 

congressional hearings, agencies, consumer groups, scholars, security companies, news 

media, and users of filesharing programs. These reports have arisen from sources on both 

sides of the filesharing debate and sources largely unconcerned with that debate. While 

these reports do not—and cannot—describe the full scope of the problem, they show that 

unintentional sharing of files has recurred regularly. In the aftermath of Grokster, the 

potential implications of such reports become clear enough to warrant investigation. 

B. This report investigates whether popular filesharing programs contain 

features that their distributors knew or should have known could cause 

users to upload files inadvertently. 

Appendix A provides more detail about the factors that shaped the scope of this report, 

and it defines some of the terms used. Consequently, this section will simply outline the 

8
scope of the issues that this report addresses. This report reviews only publicly available 

data, and it seeks to answer two questions. 

First: Do popular search-and-download filesharing programs contain—or have they 

contained—features that can cause users to share files unintentionally? This report will 

focus on five such programs: KaZaA, LimeWire, BearShare, eDonkey, and Morpheus.11 

It will examine how the sharing-related features of these programs operate, and how their 

operation did or did not change from 2002 through 2006. 

Second: Do the circumstances surrounding the use of any such features suggest a need to 

further investigate whether any particular distributor that deployed such a feature 

intended for it to dupe users into sharing files inadvertently? This report does not purport 

to determine whether any particular distributor intended to dupe users by deploying a 

feature with a known or obvious propensity to cause inexperienced users to share files 

inadvertently. To be sure, intent might be inferred from unrebutted public data showing 

that a particular distributor deployed a feature that had a known propensity to cause users 

to share files inadvertently. But even in such a case, a distributor might possess 

nonpublic data that would tend to show that the feature at issue was actually deployed 

innocently, negligently, or recklessly. 

It is important to note that a report that seeks to answer the two questions described above 

will not answer many other important questions. Filesharing programs raise an array of

public-policy and public-safety concerns, and only a few of them will be addressed in

detail in this report. 

This report focuses on features that could mislead users into sharing files inadvertently: It 

does not discuss features that might dupe users into performing other actions. For 

example, by default, most filesharing programs make a user’s computer eligible to serve 

as a “supernode” or “ultrapeer.” It seems highly unlikely that most users realize that this 

means that they have “agreed” to house—on their computers—search-index servers much 

like those that subjected Napster, Inc. to billion-dollar secondary liability or those that 

subjected operators of Direct Connect “hubs” to criminal prosecution and conviction.12 

Nevertheless, housing a search-index server does not cause users to share their own files 

inadvertently, so the issue will not be discussed further here. 

This report also focuses on features that could indicate intent to dupe users into sharing 

files inadvertently or unintentionally: It does not discuss features in popular filesharing 

programs that encourage users to sharing infringing files intentionally. Many potential 

examples of such features exist: 

• Versions of the KaZaA filesharing program contained a “Participation Level” 

feature that creates strong incentives for users to share files that other users want 

to download. As Grokster notes, such files strongly tend to be infringing. 

• Professor Strahilevitz argues that filesharing programs encourage new or 

unsophisticated users to share files through “charismatic code” that “presents each 

member of a community with a distorted picture of his fellow community 

9
members by magnifying cooperative behavior and masking uncooperative 

behavior.” Deceit gives this code its “charisma”: “While there is nothing terribly 

persuasive about telling a lie per se, the genius of Gnutella is the way in which it 

makes that lie look like a reality to its users.”13

Under Grokster, such features might be relevant to an analysis of inducement-bypersuasion. Nevertheless, features that encourage users to intentionally share infringing 

files do not suggest duping, so they are not a focus of this report. 

Finally, this report does not assess all security risks associated with filesharing programs. 

At least two types of security risks fall outside of its scope. First, filesharing programs 

themselves may contain bugs or flaws that hackers can exploit to compromise computers 

or networks. Second, filesharing programs can download mislabeled files that contain 

malicious code that can compromise computers and networks. These vulnerabilities are 

significant, but neither is a focus of this report. 

III. An Analysis of Potential “Technological Features To Induce Users to Share” in 

Five Popular Filesharing Programs. 

A potential link between filesharing programs and duping schemes first appears in the 

2000 study Free Riding on Gnutella, one of the most widely cited scientific studies of 

post-Napster filesharing networks.14 In 2000, early filesharing programs based upon the 

Gnutella protocol had similar uploading and downloading capabilities: A user had to 

make a conscious decision and act affirmatively in order to download or upload any 

particular file.15

Researchers from Xerox PARC Labs studied the resulting network in August of 2000 and 

concluded that Gnutella-based networks would not be robust, efficient or scalable 

because so few users chose to share files: 66% shared no files at all, so 1% of all users 

provided 47% of all responses to queries for files. The Gnutella network, though entirely 

decentralized in its architecture, thus remained highly centralized in fact. 

Free Riding on Gnutella and subsequent research also noted that these low levels of

sharing were no accident: Design characteristics like anonymity, indiscriminate sharing, 

large user-bases, dynamic membership, cheap pseudonyms, and lack of central 

administration made filesharing networks suitable for infringing use, but these features 

also discouraged users from sharing files.16 Indeed, they ensured that few users would 

possess any files that they could safely and legally distribute over filesharing networks. 

For example, many parents will want to share digital photos of their children with family 

and friends. But “sharing” such photos over a filesharing network would be ineffective 

and dangerous. LimeWire has explained why it could be ineffective: “Here’s modern 

p2p’s dirty little secret: It’s actually horrible at [locating] rare stuff.”17 It would be 

dangerous because the anonymity, cheap pseudonyms, and indiscriminate sharing that 

make these networks an attractive venue for infringement also attracted “unstoppable” 

pedophiles who share violent child pornography, and, reportedly, inadvertently shared 

10
data about particular children.18 In short, if users of filesharing programs were not 

sharing files, the distributors of these programs had their own design decisions to blame. 

From their analysis, the authors of Free Riding drew the following conclusions: 

• The Gnutella network faced “possible collapse” if developers of Gnutella-based 

programs continued to rely on “voluntary cooperation between users.” 

• Developers of Gnutella-based programs could rely, instead, on “technological 

features to induce users to share.”

 19 

The study noted at least two such “features.” One was the redistribution feature used by 

Napster, Inc. that would cause users to upload files downloaded from the network. 

Another was the forced-sharing feature used by FreeNet that compels each user to store 

and share files. 

The phrase “technological features to induce users to share” is inherently interesting in a 

post-Grokster world. In itself, it might not suggest duping: Distributors could “induce” 

users to share noninfringing files or to share infringing files intentionally. But this phrase 

does suggest duping when reliance upon “technological features to induce users to share” 

is presented as an alternative to reliance upon “voluntary cooperation between users.” 

Consider, for example, the most widely deployed “technological feature” cited by Free 

Riding on Gnutella: A redistribution feature that will, by default, cause users to upload

(or “share”) all files that they download. 

A. Redistribution features can cause users to share infringing downloads 

unintentionally. 

After Free Riding on Gnutella was published, the redistribution features it recommended 

became nearly ubiquitous in filesharing programs. Some distributors reportedly 

implemented such features in response to its findings.

20 By 2002, the Gnutella protocol 

required compliant filesharing programs to contain a redistribution feature. 

Research suggests dramatic results: By mid-2001, another study of the Gnutella network 

revealed that only 25% of studied users shared no files.21 A smaller 2001 study of users 

of versions of the KaZaA and Morpheus filesharing programs that contained 

redistribution features showed that only 32% of those users shared no files: “At least part 

of this increased sharing, relative to Gnutella, surely stemmed from the defaults built into 

these systems.”22

Today, almost all popular filesharing programs contain a redistribution feature. Most 

programs implement this feature by storing downloaded files in a folder that is shared by 

default. As Free Riding on Gnutella predicted, distributors of filesharing programs assert 

that these redistribution features are essential. In a 2004 letter to six Senators, the 

distributors of KaZaA asserted that disabling KaZaA’s redistribution feature would 

11
“cripple” the KaZaA network. In an internal email, Altnet asserted that “p2p exists 

because of this feature.”23 

Obscure or poorly disclosed redistribution features that tend to cause new or 

unsophisticated users to share downloaded files inadvertently could assist filesharing 

networks in two ways. First, they could help networks scale by ensuring that popular 

downloads are widely shared. Second, they would ensure that more users would share 

files with the same hash value: This would facilitate “swarming” downloads in which 

users download pieces of the same file simultaneously from multiple sources.24

Commentators have repeatedly concluded that redistribution features cause users to 

“share” downloaded files unintentionally. For example, in 2003, Professor Strahilevitz 

concluded that these features cause “unsophisticated or ambivalent users to make their 

files available for others to download.”25

Similarly, in 2004, a neutral amicus brief to a Federal court from five professors of 

intellectual-property law from Harvard Law School’s Berkman Center for the Internet 

and Society concluded that “only the most sophisticated” high-volume uploaders of 

infringing files intend to share any files: “Many users may not be aware that 

redistribution is automatically enabled by default.” These scholars warned that 

distributors create “technological barriers” to ensure that “disabling file-sharing ... can be 

[a] very difficult, and perhaps impossible, task for all but the most expert computer 

users.”26

Professor Sag drew similar conclusions: “[P]eer-to-peer networks are programmed to 

create strong incentives to upload.... In part, this is achieved by burying the pro-sharing 

default so that it takes some user sophistication to figure out how to turn it off.”27

These conclusions accord with reports from users of filesharing programs. Beginning in 

mid 2003, some copyright holders began suing users of filesharing programs alleged to 

be uploading many hundreds of infringing files. Sued users soon reported that they did 

not know that they were “sharing” the files that they had downloaded. The profilesharing website p2pnet.net characterizes their complaints as follows: 

It seems most of the RIAA’s victims, including young children, used 

KaZaA.... They also say Sharman failed to make it clear that the folder in 

which KaZaA downloads were stored needed to be disabled so other 

people couldn’t tap into it. But even if they had known, figuring out how

to disable the folder was beyond them, say victims, especially children.28 

While several of these sources explain why users might have difficulty disabling 

redistribution features, none explains why users might overlook redistribution features. 

But Free Riding on Gnutella shows that most users of filesharing programs do not want 

to share files; they only want to download files shared by others. For two reasons, users 

who only want to download can overlook a program’s redistribution feature. 

12
First, users who only intend to download files have no incentive to explore the sharingrelated interfaces of their filesharing programs. Filesharing programs typically disclose

their redistribution features in these sharing-related interfaces. 

Second, redistribution features link the acts of downloading and uploading in a way that 

can be profoundly counterintuitive to consumers generally or even to experienced 

computer users. Ordinarily, the act of acquiring a book, CD, or DVD for personal use 

does not cause a consumer to distribute that work to others. One user who lost her life 

savings in a lawsuit stressed this point: 

I never willingly shared files with other users.... [T]he music I 

downloaded was for home, personal use. ... As far as I was concerned 

copyright infringement was what the people in Chinatown hawking 

bootlegged and fake CDs on the streetcorner were doing. ...29 

This user understood that distributing unauthorized copies of protected works constitutes 

infringement, but she did not understand that the redistribution feature in her filesharing 

program ensured that she was doing just that. 

Redistribution features could even confuse experienced computer users: Most programs

do not cause their users to automatically redistribute saved or downloaded files. For 

example, using an Internet browser to visit websites or download files does not cause the 

user to begin acting as a server for each visited website or to begin making each 

downloaded file available to strangers. 

By late 2003, distributors of filesharing programs knew or had reason to know that 

disclosing redistribution features only in sharing-related interfaces could cause users to 

share downloaded files inadvertently. Many distributors pledged to improve their 

disclosures. For example, by October of 2003, the distributors of eDonkey, BearShare, 

LimeWire, and Morpheus had drafted and published a Code of Conduct that required 

their programs to “conspicuously require the user to confirm the folder(s) containing the 

file material that the user wishes to make available to other users before making such 

material available....”30 

This conspicuous-confirmation requirement permits redistribution features—if they 

“conspicuously require the user to confirm” that he or she wishes to share downloaded 

files. Although the distributors of BearShare, eDonkey, LimeWire, and Morpheus all 

pledged to comply with this Code and repeatedly represented that they had done so, 

studied versions of their programs did not “conspicuously” require users to confirm that 

they wished to share downloaded files.31 Indeed, disclosure of redistribution features 

often decreased after the Code was drafted. 

Three basic patterns of disclosure emerge. The first is nondisclosure: A program might 

provide new or download-only users with no information that would suggest that a 

redistribution feature exists. For example, studied versions of eDonkey, like version 

1.4.3, provide no information about sharing on their main interface—by default or 

otherwise—nor do they disclose their redistribution feature during their installation-and13
setup processes.32 eDonkey 1.4.3 did not “conspicuously require the user to confirm”

that she wished to share downloaded files by default. 

But nondisclosure is better than a potentially misleading disclosure: A program

containing a redistribution feature could suggest that redistribution was disabled by 

default. Here, for example, is an interface that appears during the installation-and-setup 

process in a 2003 version of Morpheus: 

Figure 1: Morpheus 3.0.36

This version of Morpheus appears to lack a redistribution feature. Big black text tells the 

user, “Edit your shared folders”, and the list below is empty by default. But appearances 

can deceive: This version of Morpheus has a redistribution feature—downloaded files are 

stored in a specially created “Downloads” folder that will be shared by default. 

Consequently, the information provided could be affirmatively misleading. Nor has this 

interface improved materially in the more recent versions of Morpheus. 

Finally, other disclosures decreased over time. Information can be disclosed in ways that 

make it too ambiguous to be useful. For example, in THE HITCHHIKER’S GUIDE TO THE 

GALAXY, aliens create a supercomputer called Deep Thought to calculate the meaning of 

life, the universe, and everything. After calculating for ages, Deep Thought discloses that 

the answer to the meaning of life, the universe and everthing is “42.” Just “42.” This 

disclosure does not really illuminate the meaning of life. 

Fortunately, real-world filesharing programs have provided main-interface disclosures 

about sharing more useful than the information provided by the fictional computer Deep 

Thought. One of the best of these displays appears in 2003 and 2004 versions of 

LimeWire. This display appeared at the bottom left of the main interface: 

14
Figure 2: LimeWire 4.0.7 

This display is not perfect: It does not clearly inform the user that they are the one sharing 

these files. Users migrating from KaZaA might find this ambiguity particularly 

confusing because the lower left of the KaZaA main interface provides information about 

files shared by other users of the KaZaA program. Nor does this display reveal how the 

user might disable the sharing disclosed. Nevertheless, this display could provide useful 

information to some users and with minor modifications, it might have been even more 

informative. 

Given that this best-of-class display could have easily become even more useful and 

informative, one might wonder whether it has changed over time. It has. In early 2006, 

this display looked like this: 

Figure 3: LimeWire 4.10.9 

“42.” Just “42.” In other words, this user is sharing 42 files. LimeWire’s once-useful 

display became a real-world implementation of Deep Thought. 

In summary, some programs disclosed less information about their redistribution features 

after the filing of copyright-enforcement lawsuits made this information more important 

to users. This suggests that redistribution feature can cause new or unsophisticated users 

to share downloaded files inadvertently. But as potential duping schemes, redistribution 

features would have two weaknesses. 

First, redistribution features are not really that difficult to detect or disable. While the 

deployment of redistribution features may have radically increased users’ propensity to 

share files in 2001, their effects soon faded: For example, a study using data collected in 

mid-2002 reported that 42% of studied Gnutella users shared no files.33 

Second, redistribution features cannot add new content to a network. In particular, they 

cannot cause users to inadvertently share the large collections of existing media files 

stored on their computers, (such as those copied from purchased CDs).34

Consequently, a distributor might deploy other “technological features to induce users to 

share” that would compensate for these inherent weaknesses of redistribution features. It 

thus becomes important to determine whether popular filesharing programs have 

contained, or do contain, features that could cause users to inadvertently share existing 

files already stored on their computers. 

All five programs examined have contained such features. Many still do. 

15
B. Search-wizard and share-folder features can cause users to infringe 

copyrights—or jeopardize their own financial or personal safety—by 

sharing existing files inadvertently. 

In mid-2002, computer-science researchers from HP Labs showed that distributors of 

filesharing programs had deployed two features that could cause users to inadvertently 

share existing files stored on their computers: 

• Search-wizard features: Search wizards may activate automatically, or they may 

be activated by the user. When activated, these features scan portions of a user’s 

hard drive and then identify folders that contain “triggering” file types, which 

usually include audio files, audiovisual files, and document files. A list of

identified folders is then displayed. Some search wizards merely recommend 

sharing of listed folders—these folders will be shared only if the user checks an 

associated checkbox. Others will automatically select all listed folders for 

sharing. Search wizards were often included in filesharing programs’ installationand-setup processes; they may also be accessed from menus within the programs. 

• Share-folder features: By default, most filesharing programs store downloaded 

files in a folder created by the program during installation. A share-folder feature 

lets the user select a different folder to store downloaded files. But it does so 

through an interface that does not clearly warn the user that the selected folder, 

and usually its subfolders, will be “shared” with other users.35

These search-wizard and share-folder features usually cause recursive sharing: They will 

“share” not only the files stored in a folder selected by a search-wizard or share-folder 

feature, but also files stored in any subfolder of the selected folder. In short, a recursivesharing search-wizard or share-folder feature treats a user’s instruction to store files in, or 

share, one folder as an authorization to share that folder and many other folders and files. 

The inadvertent sharing of existing folders and files can have dangerous effects. Like 

inadvertent sharing of downloaded files, inadvertent sharing of existing files can make a 

user a high-volume uploader of infringing files. For example, a user might try to store 

downloaded files in his “My Documents” or “My Music” folder because these folders 

probably contain no existing files, only subfolders. Recursive sharing would then cause 

this user to “share” the thousands of audio files copied from purchased CDs stored in 

subfolders of “My Music.” 

But inadvertent sharing of existing files can also have other effects—thanks to a postNapster change in the design of most filesharing programs. Napster, Inc.’s filesharing 

program shared only audio files. After the Napster litigation, distributors of filesharing 

programs were advised to bolster their capacity-for-substantial-noninfringing-use defense 

by redesigning their programs to share almost all types of files by default: “[I]f you’re 

developing a file-sharing system or distributed search engine, support all file types, not 

just MP3 or Divx files.”36 Such advice was widely followed: KaZaA, LimeWire, 

BearShare, eDonkey, and Morpheus now share almost all types of files by default. 

16
This changed behavior makes inadvertent sharing of existing files very dangerous. Most 

computers now store files containing highly sensitive information.37 These files may 

contain sensitive personal information—credit card data, financial information, tax 

returns, scans of legal or medical records, digital photographs, personal correspondence, 

business documents, or other similar files. They may also contain sensitive information 

owned by an employer or another user of the computer. Inadvertent sharing of such files 

could result in identity theft, disclosure of trade secrets, economic espionage, or worse.38 

Because inadvertent sharing of existing files and folders can have such serious 

consequences, it is critical to note how this problem was called to the attention of 

distributors of filesharing programs, how they responded, and what happened afterwards. 

In the June 2002 study Usability and Privacy: A Study of KaZaA P2P File-Sharing, 

researchers Nathaniel Good and Aaron Krekelberg showed that users of the KaZaA 

filesharing program were sharing so many sensitive personal files that identity thieves

had begun data-mining the KaZaA network for inadvertently shared credit-card data.39

To determine why users were sharing files inadvertently, Usability and Privacy 

developed four usability guidelines for responsible developers of filesharing programs 

and conducted a user study. The users studied were adults, and almost all of them were 

relatively sophisticated: All were regular computer users; all “were given a short tutorial 

on file sharing, and the concept of a shared folder”; and 83% had previously used 

filesharing programs. 

Based upon the usability guidelines and the user study, Usability and Privacy concluded 

that KaZaA was unsafe. Its user interface was “weighted too heavily in favor of sharing 

files.” Usability and Privacy revealed two features in the KaZaA interface that could 

cause users to share existing files inadvertently. These were the KaZaA share-folder and 

search-wizard features.40

The KaZaA share-folder feature was accessed from the program’s “Options” menu. It 

would present the user with the following interface: 

Figure 4: KaZaA 1.7.1 

17
Usability and Privacy summarized the problems with the KaZaA share-folder feature: 

“The word “folder” is singular, implying one folder, and does not hint that all folders 

below it will be recursively shared with others.” Worse still, “the name ‘download 

folder’ implies that it will be used to store files that are downloaded and has nothing to do 

with sharing. It does not mention that this folder (and the folders and files underneath) 

will also be shared with others....” Indeed, the KaZaA share-folder feature gave users

only one obscure hint that the “download folder” might be shared: A checkbox near the 

bottom of the interface was labeled “Disable sharing of files with other KaZaA users.” 

The KaZaA search-wizard feature had changed over time. In versions before 1.7.1, the 

wizard could be accessed during the program’s installation-and-setup process, (when the 

user would be most unfamiliar with the program), and from the “Options” menu within 

the installed program. In versions 1.7 to 2.4, the wizard could only be accessed from the 

“Options” menu within the program. It was inactive by default, but if activated by the 

user, it would produce a results screen like this one: 

Figure 5: KaZaA 1.7.1 

The results screen shown above shows the KaZaA search wizard “recommending” that 

the user share his “My Documents” folder. Note that “My Documents” will be shared 

only if the user checks the checkbox to the left of the folder path. But the user is not 

warned that “My Documents” will be shared recursively, and this information is essential 

if the user is to react intelligently to the absurd “recommendation” to share “My 

Documents.” 

Usability and Privacy cited many other problems with the results screen, including the 

following: (1) “it does not say what files in the ‘My Documents’ folder will be shared,” 

(2) it “relies on the user’s knowledge of what is capable of being shared by a file sharing 

program,” and (3) “[i]t presumes that users have perfect knowledge of what kinds of files 

(and sub-directories with further files) are contained in these folders and that these 

18
contents will be recursively shared.” The study also confirmed that these presumptions 

did not correlate with reality: It noted, “Novice users are ‘notoriously bad’ at navigating 

hierarchical file structures,” and it revealed that 75% of the users studied “believed that

only multimedia files such as music, video and pictures could be shared.” 

Usability and Privacy concluded that “file sharing software is safe and usable if users ... 

are clearly made aware of what files are being offered for others to download [and] do 

not make dangerous errors that can lead to unintentionally sharing private files...” It 

concluded that KaZaA failed to satisfy these standards. It warned that “lessons learned 

from KaZaA are applicable to designers working with other P2P systems,” and that “the 

potential violation of user privacy and the current abuses that we noted” meant that 

eliminating features that were causing inadvertent sharing of existing files “should be a 

top priority for file sharing applications....” 

Because inadvertent sharing of existing files had such dangerous consequences, Usability 

and Privacy prompted two congressional hearings. During a hearing before the House 

Committee on Government Reform, staff investigators confirmed that thousands of users 

of filesharing programs were inadvertently sharing data files for popular financemanagement software that could contain account numbers and detailed records about a 

user’s finances.41 During a hearing before the Senate Committee on the Judiciary, 

legislators repeatedly warned distributors that unless they eliminated features that caused 

users to share existing files inadvertently, their programs would compromise national 

security: 

• “[I]n government agencies, employee use of P2P networks could ... disclose 

sensitive government data to the enemies of this country.” 

• “[I]f the user is a government employee ... sensitive government information 

could be made available to those unfriendly to the United States.” 

• “For government users, the situation is far worse. Not only personally sensitive 

information can be stolen, but information vital to the functioning of government, 

as well. Confidential memos, Defense Department information, law enforcement 

records, all could be available to any Internet user with some free software and 

the desire to go looking.”42

In the aftermath of Usability and Privacy and the hearings, distributors of various 

filesharing programs were differently situated as to the problems identified. One needed 

only to refrain from adding features that had been shown to cause users to share existing

files inadvertently. Usability and Privacy had noted that inadvertent sharing of sensitive 

files was less common on the Gnutella network. The design of the Gnutella-based 

program LimeWire may explain why: From at least the beginning of 2002 through June 

2003, LimeWire contained neither a search-wizard nor a share-folder feature. 

But most distributors of popular filesharing programs had deployed share-folder or 

search-wizard features. During the hearings, the distributors of KaZaA assured 

legislators, “[W]e welcome intelligent research like that done by Good and Krekelberg 

19
and we always incorporate it into our product development plans.”43 They promised that 

the forthcoming release of KaZaA 2.5 would redress the identified problems. 

After the hearings, other distributors claimed that they too had moved swiftly to redress 

inadvertent sharing of existing files. For example, on September 29, 2003, the 

distributors of Morpheus, BearShare, LimeWire, and eDonkey published a Code of 

Conduct that imposed the following obligations: 

• “[Our] software and associated user instructions shall conspicuously require the 

user to confirm the folder(s) containing the file material that the user wishes to 

make available to other users before making such material available, and” 

• “[Our] software and associated user instructions ... shall be designed to 

reasonably prevent the inadvertent designation of the content of the user’s ... 

principal data repository ... as material available to other users.”44

On its face, the Code bars the use of KaZaA-like share-folder and search-wizard features 

on two separate grounds: Those features did not “conspicuously” require users to confirm

that they wished to share all the folders that these features would actually share, and they 

were not designed “to reasonably prevent” sharing of a user’s principal data repository. 

More importantly, the Code’s generally worded obligations also prohibit virtually any 

other feature that might cause inadvertent sharing—including, for example, a poorly 

disclosed redistribution feature. 

Consequently, by September 29, 2003, the distributors of all of the programs studied in 

this report had declared that they would end the use of KaZaA-like share-folder or 

search-wizard features. These declarations also seemed credible: Usability and Privacy 

and the 2003 hearings had not treated misleading search-wizard and share-folder features 

as potential duping schemes. To the contrary, they were treated as mistakes in interface 

design that responsible distributors should correct. 

Indeed, by mid 2004, distributors were claiming that they had responded so thoroughly 

that the problem of inadvertent sharing of existing files had become a mere “urban 

myth.” On June 23, 2004, the distributors of Morpheus, BearShare, and eDonkey 

testified to a Senate Subcommittee that they had created “safeguards” that would “render 

the feared ‘broadcast’ of personal data to ‘millions of others of Internet users’ ... wholly 

without foundation.” They testified, “[A]s far as [we] are concerned, allegations that it is 

easy for a user to inadvertently ‘publish’ sensitive materials like ... tax information 

through our software is literally the equivalent of an urban myth....”45

This same attitude also appears in the response that the distributors of BearShare, 

eDonkey, and Morpheus offered to a frequently-asked question about whether use of a 

filesharing program increases a user’s risk of identity theft: “Absolutely nothing about 

peer-to-peer software itself ... increases the odds that a user’s personal information can 

or will be accessed by some unknown person.”46

20
On January 18, 2005, the distributors of Morpheus, BearShare, and eDonkey submitted 

the following written statement to the Federal Trade Commission: 

Myth: “Thousands” of people’s personal data—such as health, tax, and 

other financial material—has been and is inadvertently made available 

through P2P software programs, which make such breaches of personal 

security easy and whose developers don’t seem to care. 

FACT: As [we] testified before Sen. Smith last June, these allegations are 

among the most egregiously false claims about [our] software. They 

appear, however, to have the inexplicable staying power of “an urban 

myth, no more accurate—though easily as persistent—as reports of 

alligators in New York’s storm drains.” 

In fact, users of our ... software must affirmatively create and populate 

“shared” document folders and are subject to multiple cautions about the 

importance of not affirmatively placing sensitive material in them. 

Moreover only files downloaded with our ... programs are “routed to such 

shared folders.... No existing information on a users’ [sic] hard drive can 

“migrate” to those shared folders on its own.47 

These, and similar, representations certainly made it appear that distributors of filesharing 

programs had moved quickly, responsibly, and effectively to redress the problem of 

inadvertent sharing of sensitive files. 

But then, from 2004 to the present, inadvertent sharing of sensitive files began to recur: 

• CBS Marketwatch reported that BearShare users were again inadvertently sharing 

“tax returns” and “private medical files and private bank statements.” A 

BearShare spokesman said, “As I understand it, a new version will be coming out 

literally in a matter of days that will seek to close any possible vulnerabilities of 

this.”48 

• The website See What You Share reported that criminals were again mining 

filesharing networks for inadvertently shared data. It reported that identity thieves 

were searching for inadvertently shared financial data. It also reported that 

pedophiles were searching filesharing networks for hard-core child 

pornography—and for inadvertently shared data about particular children.49

• The security company Blue Security reported that inadvertent sharing had become

so widespread that spammers were “systematically” data-mining filesharing 

networks to find inadvertently shared email addresses. Blue Security found 

“hundreds of incidents where files containing email addresses were made 

accessible to any Internet user.” These incidents involved “[m]any files [that] 

contained sensitive personal and business information, for example: a list of 

professors teaching in a well known university, email addresses of pro-gay 

21
marriage supporters and a complete customer list of a certain Internet store, along 

with customer contact information.”50

Recently, Howard Schmidt, former White House cybersecurity advisor and co-author of 

the National Cyber-Security Policy, warned that inadvertent sharing has become

pervasive, affecting both corporations and individuals. He found corporations sharing 

internal audit reports, human-resource records, internal litigation documents, and security 

manuals: “I’ve seen thousands of documents containing internal administrative 

passwords which are now being shared throughout the world.” He warned, “The risk is 

that [criminals] are now searching for corporate information—P2P search strings [we’ve 

identified] show that they’re actively seeking those documents.” The problem also 

affected individuals: “In one case of this sort, a criminal searched for and found 117,000 

medical-record passwords—just by knowing how to search in a P2P app on the Web.” 

He also warned that “one woman’s credit-card information was found in such disparate 

places as Troy, Mich., Tobago, Slovenia, and a dozen other places. Why? We found that 

the ‘shared’ folder in her music-downloading application was in fact making readily 

available her entire ‘My Documents’ folder to that app’s entire P2P audience, 24 hours 

per day.” Inadvertent sharing had thus become “a major part of the current identity theft 

problem.”51

The Department of Homeland Security (DHS) also reported another consequence of 

continued inadvertent sharing of sensitive files—one both foreseeable and foreseen. In a 

bulletin sent to all Federal Agencies and all state and local agencies involved in homeland 

security, DHS warned that government employees or contractors using filesharing 

programs had repeatedly compromised national and military security: 

• “There are documented incidents of P2P file sharing where Department of 

Defense (DoD) sensitive documents have been found on non-US computers with 

no protection against hostile intelligence services.” 

• “[T]here is a military investigation ... in which classified material has been 

wrongfully disclosed using P2P.” 

• “Multiple organizations have ongoing investigations into disclosure of sensitive 

or classified material due to P2P.” 

• “These applications represent a vulnerability that cannot be afforded without a 

strong justification.”52

Given that distributors had been warned that this would happen unless they eliminated

features that could cause users to share existing files inadvertently, the DHS bulletin 

raises a question: Did distributors of popular filesharing programs actually eliminate and 

halt the effects of dangerous search-wizard and share-folder features like those 

condemned in Usability and Privacy? 

The answer to this question is “No”: None of the distributors of the five programs 

analyzed here did so. Indeed, except for the distributors of KaZaA, these distributors 

22
either began or continued to deploy either search-wizard or share-folder features, or both, 

in studied versions of their programs released during 2004 and 2005. In many cases, 

2004 and 2005 versions of these features were actually more dangerous than the searchwizard and share-folder features condemned in Usability and Privacy and the 2003 

congressional hearings. 

And as these features migrated from FastTrack to other networks, so too did the problem 

of inadvertent sharing of sensitive files. In 2002, when FastTrack-based programs like 

KaZaA were deploying search-wizard and share-folder features, a survey by the authors 

of Usability and Privacy found more inadvertent sharing on the FastTrack network than 

the Gnutella network. 

In 2004, when KaZaA had eliminated such features prospectively and many Gnutellabased programs had deployed them, another informal survey found more inadvertent 

sharing on the Gnutella network.53 An informal survey of relative levels of inadvertent 

sharing conducted for this report also indicated that inadvertent sharing of personal files 

is most prevalent on Gnutella, the network used by the programs deploying the most 

aggressive search-wizard and share-folder features in 2005. 

1. Share-folder features were widely deployed after their potential to 

cause inadvertent sharing was known. 

During 2004, 2005, and 2006, the distributors of BearShare, eDonkey, LimeWire, and 

Morpheus deployed share-folder features in studied versions of their programs. In 

BearShare, Morpheus, and LimeWire, these share-folder features would cause recursive 

sharing. Often, these features were more problematic than the KaZaA share-folder 

feature condemned in Usability and Privacy. For example, the Options Menu of a 2004 

version of LimeWire contains two sub-menus: One is titled “Saving” and the other 

“Sharing.” The “Saving” menu displays the LimeWire share-folder feature: 

Figure 6: LimeWire 4.0.7 

23
In short, the user is told that this is a “Save Directory”—and left to figure out that in 

LimeWire, “save” means “share recursively.” This is actually worse than the KaZaA 

share-folder feature: The user receives not even a hint that a folder selected as the “Save 

Directory” will be shared—much less shared recursively. Nor is the LimeWire sharefolder feature unique. 

The following screenshot shows the “Downloads” tab on the BearShare Setup menu. 

Note that there is a separate tab called “Uploads”:

Figure 7 

Again, the user gets no hint that selecting a folder to store downloaded files in the 

“Downloads” menu will recursively share all files in that folder and all files in all of its

subfolders. Nor would the BearShare User’s Guide help; it had only this to say about the 

“Downloads” menu: “Here is where you indicate where files will go when you download 

them. The default directories are entered for you, but you can change them by clicking 

‘Browse’ and entering a new location for your downloads.” Consequently neither the 

program nor its user instructions “conspicuously require the user to confirm the folder(s) 

containing the file material that the user wishes to make available to other users before 

making such material available....”54 A user does not “conspicuously confirm” that he or 

she wishes to share a particular folder by selecting it to store downloaded files through a 

menu that reveals neither that the selected folder will be shared nor that all of its 

subfolders will be shared recursively. 

24
The LimeWire and BearShare share-folder features were also more dangerous than the 

KaZaA share-folder feature for a second reason. Unlike KaZaA, LimeWire and 

BearShare incorporated share-folder features into their setup processes—a decision that 

could increase the threat that these features pose to new users. 

Share-folder features like these can have particularly devastating effects when a 

filesharing programs is used on a computer connected to a governmental, corporate, or 

home network. For example, on some networks, using a share-folder feature to store 

downloaded files in “Documents and Settings” can recursively share the files of all other 

users of the network in question. 

Moreover, the share-folder features in some recent versions of LimeWire, BearShare, 

eDonkey, and Morpheus are actually worse than they appear because they encode a 

behavior not discussed in Usability and Privacy. For example, imagine that a LimeWire 

user designates “My Music” as her “Save Directory” because this folder contains no 

existing files, only subfolders. Later, this user discovers that the recursive sharing thus 

enabled has caused her to share thousands of audio files copied from purchased CDs. 

Realizing that she has now become a copyright-enforcement target, the user re-opens the 

“Saving” menu and sees that LimeWire provides a way to correct her mistake: There is a 

“Use default” button below and to the right of the “Save Directory”: 

Figure 8: LimeWire 4.0.7 

She clicks the “Use default” button and is relieved to see that the “Save Directory” is 

instantly reset to the empty default “Shared” folder created by LimeWire: 

Figure 9: LimeWire 4.0.7 

25
A user viewing the interface shown in Figure 9 might think, “Problem solved!” But 

nothing has changed: LimeWire is still sharing all files stored in the user’s “My Music” 

folder and all of its subfolders. Share-folder features like those used by LimeWire, 

BearShare, Morpheus, and eDonkey exhibit a behavior that can be called “librarying”: A 

folder “shared” through the share-folder feature will remain shared even if the sharefolder feature is reset to its “default” setting or used to select a different folder to store 

downloaded files. A “librarying” share-folder feature is a one-way ratchet: Successive 

uses of it can only cause users to share more files and folders—never less. 

It is difficult to justify the behavior of librarying share-folder features: Even were a 

distributor to assume that users would instinctively know that any folder used to store 

downloads will always be shared by default, then this justification for sharing would end 

once a folder ceased to be used as the download folder. 

Moreover, undisclosed share-folder features would be obviously problematic even if they 

had not been specifically condemned in Usability and Privacy. If a distributor gains 

access to existing files on a user’s computer by failing to disclose that any folder used to 

stored downloaded files will be shared—or by failing to disclose that such sharing will be 

recursive—then the user has really not authorized anyone to access or download those 

files. It is illegal to gain unauthorized access to data on someone else’s computer or to 

exceed the scope of authorized access to such data.55

The LimeWire share-folder feature is particularly inexplicable. For example, in 2004, 

LimeWire purported to explain why distributors of filesharing programs had failed to 

resolve the problem of inadvertent sharing of existing files: 

We have been looking at addressing the accidental sharing issue for a 

while. Certainly, more can be done.... 

That being said, these are file sharing applications. The main goal of a file 

sharing application is to make it easy for users to share files. Users need to 

be aware of what they are doing....

Given that file sharing is still a relatively new type of application, it makes 

sense that the developers have not worked out all of the security issues. 

We are still focused on improving the P2P protocol.56

In short, LimeWire claimed that it was too busy helping others download whatever files 

users did happen to “share” to ensure that users shared only those files that they intended 

to share. Even ignoring the odd priorities thus revealed, this claim still flounders on an 

awkward fact: Researchers, Congress, and LimeWire itself had “worked out” the rather 

obvious “security issues” raised by share-folder features. 

By 2004, Usability and Privacy and two congressional hearings had already “worked 

out” the security issues raised by share-folder features. But LimeWire’s distributors had 

already “worked out” those issues for themselves. In 2001 and 2002, LimeWire would 

26
twice display the following question and warning after a user selected a new folder to 

store downloaded files: 

Figure 10: LimeWire 2.0.4 

This dialog box shows that LimeWire’s distributors needed neither published research 

nor Congress to inform them that users might not want to share an existing folder used to 

store downloaded files and that users must be warned that such a folder would be 

shared—and shared recursively—in order to make an informed decision about whether to 

share it at all. Only after Usability and Privacy was published—and its findings 

highlighted in congressional hearings—did the distributors of LimeWire modify the 

LimeWire program, remove its warnings, automate sharing of the download folder, and 

create the undisclosed, recursive-sharing, librarying share-folder feature discussed 

previously. 

 

2. Search-wizard features continued to be widely deployed after their 

potential to cause inadvertent sharing had been identified. 

In addition to share-folder features, distributors of popular file-sharing programs also 

continued, or began, to deploy search-wizard features in the aftermath of Usability and 

Privacy and the two congressional hearings. 

For example, LimeWire began to deploy a search-wizard during 2003. Like the more 

aggressive wizard in pre-1.7.1 versions of KaZaA, it was incorporated into LimeWire’s 

installation and setup process: 

27
Figure 11: LimeWire 4.10.9 

In one way, this is an improved search-wizard: The results screen states that selected 

folders will be shared recursively. But the user is only told that the wizard will scan for 

“media files”—not that it will share all files in any folder selected for sharing. Moreover, 

the notice of recursive sharing reaffirms a more fundamental defect identified by 

Usability and Privacy: Arguably, search-wizard features might assist those users who are 

“notoriously bad” at conceptualizing folder structures—those do not really know where 

in their folder hierarchy various files are stored. But to respond intelligently to a wizard’s 

recommendations, a user must have “perfect knowledge” of all the files stored in all the 

subfolders of any folder identified for potential sharing and which of those types of files 

will be shared by default. Consequently, the users who, in theory, might benefit from a 

search wizard will lack, in practice, the near-perfect knowledge of file and folder 

locations and relationships needed to respond properly to the recommendations of a 

recursive-sharing search wizard. It may thus be nearly impossible to adequately disclose 

a search-wizard or share-folder feature that causes recursive sharing. 

Like share-folder features, search-wizard features sometimes became even more 

aggressive than those condemned in Usability and Privacy. For example, here is the 

results screen from the search wizard used in a 2005 version of BearShare: 

28
Figure 12: BearShare 4.7.0.76 

Like the more aggressive version of the KaZaA search wizard, the BearShare search 

wizard appears during the installation-and-setup process—when users will be least 

familiar with the program’s behavior and its implications. But unlike the KaZaA searchwizard, the BearShare wizard selects for sharing all folders that it identifies: Once the 

wizard is triggered, every folder listed by the wizard will be shared—and shared 

recursively—unless the user acts affirmatively to prevent this. And as Figure 12 shows, 

this search wizard will select for recursive sharing the user’s “My Documents” folder. 

Public data provides no clear answer about whether Morpheus began or continued to 

deploy a search-wizard feature after mid-2003. In June of 2004, the distributors of 

Morpheus testified to a Senate Subcommittee that they had moved decisively to prevent 

users from inadvertently sharing existing files: 

[A]t no time and under no circumstances is ... any existing file on a user’s 

computer[] automatically made available to other Morpheus users. 

Rather, all the software does by default upon installation is create two 

empty folders.... 

One folder, the ‘Shared Folder’ is intended to accept files manually 

inserted by users that they wish to share. The other ‘Download Folder’ is 

where files that our users download using our software will reside... 

Thus, functionally speaking, only files downloaded to or intentionally 

placed in a user’s “Shared Folder” will be available to other P2P software 

29
users. These safeguards render the feared “broadcast” of personal data ... 

wholly without foundation. 

Unfortunately, this testimony fails to respond at all to the concerns raised in Usability 

and Privacy and the congressional hearings. Nor does it reveal whether the distributors 

of Morpheus were abiding by the Code of Conduct that they had drafted: If this testimony 

accurately described how the then-current version of Morpheus behaved, it could still 

have contained share-folder and search-wizard feature more aggressive than those 

condemned in Usability and Privacy. 

The quoted testimony is unresponsive because it proceeds from a false premise: It claims

that concerns about the “‘broadcast’ of personal data” are “wholly without foundation” 

unless a filesharing program “automatically” shares users’ existing files and folders. This 

is wrong: The KaZaA search-wizard and share-folder feature did not activate 

“automatically,” but both were problematic. Usability and Privacy had noted that while a 

“default setup [of KaZaA] where file sharing is disabled” is “relatively safe,” “user 

modification of various settings” was not safe. 

But if this testimony was otherwise accurate, then it would, at least, show that the thencurrent version of Morpheus did not contain, in its setup process, a search-wizard feature 

that was active by default and that would share identified folders by default. But if so, 

then this state of affairs may have changed. The following screenshot shows the result of 

a default installation of an early-2005 version of Morpheus. 

Figure 13: Morpheus 4.7.1.326 

This screenshot shows Morpheus sharing six folders automatically. Four of these folders 

appear to be specially created by the Morpheus program. Two of these folders appear to 

be existing folders, and one appears to be “My Documents”—though this version, like 

30
others, truncates folder pathnames in a way that makes it difficult to be sure which folder 

is being shared. In short, this screenshot may show that one or more 2005 versions of 

Morpheus incorporated a search wizard feature—one that would activate by default and 

share identified folders by default. 

Nothing more definite can be said about the meaning of this screenshot. The 4 and 5-

series versions of Morpheus install in a way that prevents the replication of the 

experiment that produced this screenshot.57 Consequently, it is possible that this version 

of Morpheus actually contained a different “feature” that can produce effects akin to 

those of a fully automatic search-wizard feature. The following hypothetical illustrates 

the potential consequences of this “feature” in a multiple-user environment like a private 

home or a college dormitory. The hypothetical uses BearShare because older versions of 

this program are more readily available. 

Suppose that a man who owns an Internet-connected home computer hosts a party for his 

relatives. During the party, a bored 13-year-old nephew leaves the gathering and installs 

BearShare onto his uncle’s computer to download some files. To make downloaded files 

easy to find, the boy sets the download folder to “My Documents,” a folder that contains 

no existing files, only subfolders. As he is downloading, the boy realizes that he has—

somehow—begun sharing thousands of files from his uncle’s computer. He exits 

BearShare and immediately uninstalls the program. Shaken, he returns to the party, 

believing that he has corrected his mistake. 

Much later, his uncle reads a report that declares filesharing programs to be “technologies 

of freedom” and “technologies of innovation.”58 Intrigued, he downloads and installs 

BearShare. The installation and setup process would reveal no information about 

sharing. Nevertheless, were this user to find the tiny “Folders” button on the Library 

interface of BearShare and drill down into the folder tree, he would find that BearShare 

had automatically and recursively shared the following folders: 

31
Figure 14: BearShare 4.7.0.76 

This happened because versions of BearShare—like some versions of LimeWire, KaZaA, 

and other programs —contain what could be called a “partial-uninstall” feature: If a user 

tries to uninstall one of these programs, the process will leave behind a file that records 

the folders shared by the uninstalled program. If anyone ever installs any subsequent 

version of the same program, the new installation will automatically begin recursively 

sharing all the folders that were shared by the uninstalled copy of the program. 

Predictably, a partial-uninstall feature violates yet another provision of the Code of 

Conduct drafted by the distributors of BearShare, eDonkey, LimeWire, and Morpheus: 

“A method by which a Member’s software (and any other software installed with it) 

readily may be uninstalled by the user shall be provided to users.” 

Nor is this a technical violation: A partial-uninstall “feature” ensures that programs like 

BearShare or Morpheus can automatically, and by default, recursively share existing files 

and folders on a user’s computer.59 As Usability and Privacy noted, most home

computers are used by more than one person. A partial-uninstall “feature” ensures that 

someone installing a filesharing program on such a computer cannot be sure what files

and folders the program will share automatically. Therefore, unless you are installing a 

filesharing program with this feature on a brand-new computer—or on a computer to 

which no other person has ever had access—then statements like the following may not 

be accurate:

[A]t no time and under no circumstances is ... any existing file on a user’s 

computer[] automatically made available to other ... users. Rather, all the 

software does by default upon installation is create two empty folders.... 

32
3. “Fixing” the effects of share-folder and search-wizard features—by 

perpetuating them. 

One more behavior relating to search-wizard and share-folder features bears note. These 

features have repeatedly caused users to share existing, sensitive or infringing files 

inadvertently. When distributors who deployed such features were “caught” causing their 

users to share sensitive files inadvertently, they responded by claiming that new versions 

of their programs would correct inadvertent sharing caused by previous versions: 

• KaZaA (2003): “[W]e changed a lot of the settings so that users wouldn’t be 

inadvertently sharing files.”60

• LimeWire (2004): “The LimeWire installation is a little dangerous for people who 

don’t pay attention, and we’ll have to address this issue in future releases ....”61

• BearShare (2005): “[A] new version will be coming out literally in a matter of 

days that will seek to close any possible vulnerabilities of this.”62 

In two out of three of these cases, the promised improvements were not delivered. For 

example, the installation-and-setup process in LimeWire 4.10.9 seems unimproved from 

2004 versions. BearShare kept its librarying, recursive-sharing share-folder feature in its 

program but removed the search wizard from its setup process. By contrast, KaZaA 2.5 

did eliminate previously deployed search-wizard or share-folder features. 

But even in the cases of KaZaA and BearShare, only new users of these programs—those 

who had never before installed any previous version of these programs on their 

computer—would have benefited from these changes. In the case of KaZaA, that benefit 

was probably material. In the case of BearShare, it appears marginal. 

But the vast installed base of existing users of these programs—those upgrading from the 

prior versions of KaZaA or BearShare that contained features that had caused inadvertent 

sharing—did not benefit from these changes: Existing users never had their filesharing 

preferences reset or rechecked. In effect, distributors who responded to incidents of 

inadvertent sharing by changing share-folder or search-wizard features created an 

appearance of improvement that actually perpetuated inadvertent sharing caused by 

previous, (and concededly defective), versions of their programs. 

The distributors of BearShare may have further “perpetuated” these effects with bad 

advice that could increase users’ risk of sharing files inadvertently. After converting 

inadvertent sharing of tax returns from an “urban myth” to a grim reality, BearShare’s 

distributors published An Important Word from BearShare about Keeping Your Private 

Files Private and an Important Privacy Notice for Users of BearShare Version 4.7.2 and 

Earlier.

63 Readers of the Important Word and the Important Privacy Notice were told 

two myths about inadvertent sharing: 

• Myth: In BearShare, you can inadvertently share existing files only during 

the installation-and-setup process. “After BearShare is installed, non33
downloaded files not specifically saved to the [‘My Downloads’] folder will not 

be accessible to other BearShare users.... [A]fter the installation process is 

complete, the only non-downloaded files that can be shared with others through 

BearShare are files that you deliberately move or copy to the shared folder.”

• FACT: BearShare’s share-folder feature ensures that users can 

inadvertently share “non-downloaded” files from within the program. 

Before and after version 4.7.2, BearShare contained an undisclosed, recursivesharing, librarying share-folder feature accessible from within the installed 

program. So “non-downloaded” files “can be shared with others through 

BearShare” without being “deliberately move[d] or cop[ied] to the shared folder.” 

• Myth: To tell whether you are sharing existing sensitive files as a result of the 

search wizards in BearShare version 4.7.2 and lower, just check your “My 

Downloads” folder: “During the installation process, BearShare will ask you 

whether you wish BearShare to include files already on your computer in a new 

shared folder [called ‘My Downloads’]. (This [search-wizard] option is presented 

on the ‘Select Drives’ screen.)... If you do not check any of the boxes next to the 

listed drives, no information on your computer at the time of installation will be 

included in your shared folder. HOWEVER, checking one or more listed drives 

will ‘populate’ your shared folder with existing files from the source(s) you have 

checked. If you checked one or more drives upon installation, or if you're not 

sure whether this was done, PLEASE CHECK THE CONTENTS OF YOUR 

SHARED FOLDER NOW TO BE CERTAIN THAT IT DOES NOT CONTAIN 

ANY FILES THAT YOU DO NOT WISH TO SHARE; PARTICULARLY 

FILES CONTAINING SENSITIVE PERSONAL INFORMATION....”

• FACT: pre-4.7.2 BearShare search-wizards did not “populate” a user’s “My 

Downloads” folder by copying existing files and folders into it. In studied pre4.7.2 versions of BearShare, search wizards shared existing files from their 

existing locations—they did not “include” those files in the user’s “My 

Downloads” folder. As a result, a user recursively sharing his “My Documents” 

folder could check his “My Downloads” folder and find no sharing of any

sensitive files. BearShare’s distributors thus told users to look for inadvertent 

sharing of existing files in the one place in which it would almost never be found. 

Each of these claims from the Important Word and the Important Privacy Notice is 

inaccurate. Neither could have been made by someone who understood how pre- and 

post-4.7.2 versions of BearShare actually worked. 

BearShare’s Important Word and Important Privacy Notice merely highlight a question 

that echoes through the short, ugly history of share-folder and search-wizard features: 

Why? Why did distributors keep deploying these obviously dangerous features after their 

propensity to harm users was repeatedly identified?

Public data cannot answer this question: It cannot reveal why the distributors of 

BearShare, eDonkey, LimeWire, and Morpheus began or continued to deploy dangerous 

34
share-folder and search-wizard features during 2003, 2004, and 2005. But by doing so, 

they made a mockery of their own Code of Conduct. They also undermined the accuracy 

of their representations to Congress, Federal agencies, state attorneys general and the 

public. They eviscerated claims that responsible distributors of filesharing programs can 

self-regulate. And they may have helped achieve the previously inconceivable result of 

converting copyright piracy into a threat to national security. 

But public data does reveal that while implementations of search-wizard and share-folder 

features recurred and worsened, the distributors deploying these features were again 

confronting an old problem—one that had recurred and worsened: Users of their 

programs no longer wanted to share files. Indeed, by mid-2004, users’ desire to share 

files had declined so precipitously that researchers again concluded that the Gnutella 

network was on the verge of “collapse.” 

4. Free Riding on Gnutella Revisited: The Bell Tolls? 

By mid-2004, distributors of popular filesharing programs were still deploying an array 

of features that had been shown to cause users to share files inadvertently. Inadequately 

disclosed redistribution features were common. Share-folder features were deployed in 

BearShare, eDonkey, Morpheus, and LimeWire. Search-wizard features were deployed 

in BearShare and LimeWire, and, it is unclear whether such a feature was, or would be, 

deployed in Morpheus. But by this time, two things had changed. 

First, high-profile, well-publicized copyright-enforcement lawsuits had heightened public 

awareness of the consequences of sharing infringing files. Users thus had stronger 

incentives to avoid or limit the sharing of infringing files, particularly audio files. 

Second, concerned users of filesharing programs could now find what distributors of 

filesharing programs had not provided: Detailed, program-specific, step-by-step, 

screenshot-illustrated instructions on how to disable sharing caused by redistribution, 

share-folder, and search-wizard features.64 These instructions on how and why to disable 

sharing were provided by public interest groups, universities, and ISPs. EFF argues that 

these stop-sharing campaigns blunted the deterrent effects of copyright-enforcement 

lawsuits against users: 

To the extent file sharers are worried about the RIAA lawsuits, many are 

simply opting to continue downloading while refraining from uploading 

(this is known as “leeching” in the lexicon of the P2P world). Because the 

RIAA lawsuit campaign has, thus far, only targeted uploaders, leechers 

can continue downloading, evidently without risk.65

 But if culpable users had stopped uploading the infringing files that they were 

downloading, this would suggest that sharing was decreasing. It would also suggest that 

distributors of filesharing programs using duping schemes to populate their networks 

with infringing files needed to evolve those schemes to counter this trend. 

35
Coincidentally, in May of 2004, a team of computer-science researchers replicated much 

of the analysis performed in the 2000 study Free Riding on Gnutella. 

In Free Riding on Gnutella Revisited, The Bell Tolls, the researchers reported that users’ 

propensity to share files had decreased sharply: “Our results indicate that 85 percent of 

peers share no files.”66 Moreover, users who did share files still rarely shared popular 

files: The data presented showed that 1% of users now returned 50% of all responses to 

search queries. 

Revisited also confirmed that “a significant volume of queries target copyrighted 

materials and that a similar proportion of responses refer to copyrighted files.” It thus 

proposed that a “positive feedback loop” was discouraged sharing: Copyright 

enforcement discouraged sharing; this made those still sharing more vulnerable; and this 

increased vulnerability further discouraged sharing. Revisited thus concluded that if 

levels of sharing remained low and enforcement continued, “the logical conclusion of

both trends will be the Gnutella network’s collapse.” 

Revisited also proposed an answer to a longstanding question: Free-Riding on Gnutella 

had identified at least two “technological features to induce users to share”—a 

redistribution feature and a “forced sharing” feature that would compel users to share 

files. But while redistribution features became ubiquitous, forced-sharing features 

remained very rare. Revisited proposed that users’ increasing desire to “leech” prevented 

distributors from deploying features that “enforced sharing of downloaded files”: 

Distributors who deployed such features would quickly see 85% of their revenuegenerating (but “leeching”) users defect to other programs.67

For example, distributors could have encouraged sharing by deploying redistribution 

features that users could not disable. But such features—particularly if their effects were 

obvious and disclosed—would impose equal burdens upon both new and sophisticated 

users: Both groups could avoid sharing only by incurring the tedium and risks of copying 

downloaded files to a non-shared folder and then deleting them from the download 

folder. These burdens and risks might cause culpable “leechers” to defect. 

But if sophisticated, culpable users would defect unless they could leech, then a 

distributor could make it more difficult for new or unsophisticated users to stop sharing 

files while ensuring that more sophisticated users could do so. Such a distributor might 

deploy what could be called a “coerced-sharing” feature: This type of feature would be 

neither obvious nor fully disclosed. It would make it difficult to disable sharing of the 

download folder while providing potentially misleading feedback suggesting, incorrectly, 

that sharing of the download folder could be easily disabled. Nevertheless, such a feature 

would provide a mechanism—an obscure, nonintuitive mechanism—that would let 

sophisticated users disable sharing of the download folder.68 Of course, this sort of 

coerced-sharing feature would blatantly violate the conspicuous-confirmation 

requirement imposed by the Code of Conduct drafted by the distributors of BearShare, 

eDonkey, LimeWire, and Morpheus. 

36
C. Recently, filesharing programs have deployed potentially misleading 

coerced-sharing features that make it difficult, but possible, for users to 

stop sharing downloaded files. 

By mid 2005, BearShare, eDonkey, LimeWire, and Morpheus contained a coercedsharing feature.69 In each case, the feature could mislead new or unsophisticated users 

into believing that they had disabled sharing of the download folder. And in each case,

there appears to be a mechanism—an obscure, nonintuitive, mechanism—that would let 

sophisticated users stop sharing the download folder.70 Often, these coerced-sharing 

features appear to be recent additions to programs that once let users stop sharing their 

download folder. 

For example, before mid-2005, version of Morpheus let users stop sharing the folder used 

to store downloaded files. More recent versions of Morpheus make it difficult for users 

to stop sharing the download folder, though some Morpheus users may think otherwise. 

Recall the Morpheus 3.0.36 setup screen presented above in Figure 1. Three years later, 

the analogous setup screen in a 2006 version of Morpheus looked like this: 

Figure 15: Morpheus 5.1.2 

Note that the “edit your shared files” instruction has now vanished: The user must read to 

the end of the small, asterisked text at the bottom to find out what this interface is. Only 

one folder is listed, “Morpheus Shared.” This folder will never store any files unless the 

user manually copies or moves files into it. But a few users might know—and others 

might guess—that the default download folder, “Downloads” is actually a subfolder of 

the “Morpheus Shared” folder displayed in the shared-folder list. Such users might also 

note that the “Include Sub Directories” checkbox is checked by default, and then select 

“Morpheus Shared” and click the “Remove” button to disable sharing. If they do, 

Morpheus would provide the following feedback on the consequences of their acts: 

37
Figure 16: Morpheus 5.1.2 

Users could reasonably conclude that this once-populated, now-empty “shared folders 

directory” indicates that they are not sharing any folders. But that is wrong: Morpheus is 

still sharing the download folder. Nor will the share/unshare interface within the program

disable sharing of the download folder: Morpheus now has a coerced-sharing feature. 

This feature upends the Code’s conspicuous-confirmation requirement: If users 

“conspicuously confirm” that they do not want to share the download folder, the program

shares it anyway. 

Users installing BearShare can also receive misleading feedback. During setup, 

BearShare presents users with a “Folder List” screen and the instruction “Check the 

folders that you want to add to your Library”: 

38
Figure 17: BearShare 5.2.3.7 

If users correctly guess that “add to your Library” means “share”—and open the 

“Legends” submenu or guess correctly—then users will realize that BearShare’s “Folder 

List” outlines a folder’s checkbox in grey if neither it nor any of its subfolders will be 

shared, but it outlines a folder’s checkbox in red if it contains a shared subfolder. Such 

users might then realize that BearShare shares at least one folder by default. Users might 

then try to halt this sharing by clicking the “Deselect All” button. If so, this is what users 

will see: 

39
Figure 18: BearShare 5.2.3.7 

If the information reported conformed to BearShare’s feedback rules, then Figure 18 

would show that BearShare is not sharing any folder on the user’s computer. But Figure 

18 actually shows that BearShare violates its feedback rules: It is still sharing the 

downloads folder. In fact, clicking the “Deselect All” button during a default installation 

of BearShare has only one effect: It causes red checkbox outlines to turn grey. Nor will 

BearShare’s internal share/unshared interface let users stop sharing the download folder: 

BearShare has a coerced-sharing feature. 

Many programs also provide potentially misleading feedback about sharing of the 

download folder from within the program itself. For example, attempts to disable sharing 

from within Morpheus or BearShare can produce much the same misleading feedback as 

attempts to disable sharing during installation and setup. 

BearShare will also inform users that they have stopped sharing files that they are still 

sharing. For example, Figure 19, below, shows the “Uploads” menu in a 2005 version of 

BearShare that is sharing 145 files from “My Downloads,” a folder included in the user’s 

“Library.” In the upper right of the Uploads menu is a checkbox labeled “Share files 

from library.” That box is checked by default. A user who wants to stop sharing 

downloaded files has now “unchecked” it, and BearShare has popped up a dialog box: 

40
Figure 19: BearShare 4.7.0.76 

In many programs, attempts to take certain actions will produce a dialog box that reminds 

the user that if they take action X, that will have effect Y, and then asks, “Would you like 

to continue?” Here, BearShare notes, “Only when users share files is it possible for 

everyone to find the files that they want to download. Please share.” BearShare then 

asks, “Would you like to continue .... Sharing?”

So the user could only complete the action that she indicated that she wanted to take by 

selecting the counterintuitive answer “No.” If she answers “Yes,” she will continue 

sharing. And what happens if BearShare asks the user “Would you like to continue 

sharing?” and the user answers “No”? 

The user will continue sharing. To be sure, the main interface will show that the user has 

“Unshared” all previously shared files, but if the user opens the Library view in 

BearShare and right-clicks upon individual files, she will learn that those “Unshared” 

files are actually still being shared. 

eDonkey can also confuse. eDonkey does not provide any misleading feedback about the 

user’s ability to disable redistribution during installation and setup because that process 

never discloses eDonkey’s redistribution feature. Within the program itself, eDonkey lets 

users share and “unshare” various folders through a graphical share/unshared interface. 

In this interface, eDonkey identifies “shared” folders with a bright-green, checked circle 

that looks like this: 

41
Figure 20 

Using this information about the behavior of the eDonkey share/unshare interface, try to 

find the shared folder in the following screenshot: 

Figure 21: eDonkey 1.4.3 

The task is challenging because the shared folder looks like it is not being shared. The 

shared folder is the default download folder, “eDonkey 2000 Downloads.” It looks like a 

non-shared folder because the user tried to stop sharing this folder by selecting it and 

clicking the “unshare” button at the top of the graphic interface shown in Figure 21. The 

user’s actions did make the checked green circle disappear, but eDonkey kept on sharing 

the download folder. Indeed, there is no obvious way for a user to disable sharing of the 

download folder in any eDonkey interface: eDonkey has a coerced-sharing feature. 

This behavior might be the result of a bug that somehow remained undetected, for years. 

But, as shown below, the design of eDonkey itself may suggest otherwise: 

42
Figure 22: eDonkey 1.4.3 

This screen shot shows a larger portion of the eDonkey screenshot shown in Figure 21. 

This larger view shows several things. Note that eDonkey actually has two share/unshare 

interfaces. The graphical share/unshared interface occupies most of the screen, but below 

it, there is a text-based share/unshare interface. 

Here, these two interfaces provide conflicting accounts of whether the download folder is 

being shared: The large graphic interface says “no,” and the small, text-based interface 

says “yes.” But readers of this report know what the user would have to guess: The textbased interface is the one delivering accurate information. Indeed, if a user right-clicks 

the download folder in the text-based interface, an “unshare” button will appear, but it 

will be grayed-out and inactive, suggesting (incorrectly) that eDonkey will not let users 

disable sharing of the download folder. Nevertheless, the text-based interface shows that 

eDonkey can provide users with correct information about whether the download folder 

is shared. 

And there is something else odd about the graphic interface. It is always updated 

instantly whenever a user shares or unshares a folder. If a user selects “My Documents” 

and clicks “share,” checked green circles appear. If a user selects the same folder and 

clicks “unshare,” checked green circles disappear. No matter which folder a user shares 

or unshares, the changes appear immediately and are implemented immediately. So why, 

in the upper right of the graphic interface, is there a button labeled “refresh”? 

Usually, that “refresh” button is worse than useless: It does not affect the information 

displayed, but clicking it collapses the portion of the folder tree being viewed, so most 

43
users probably learn not to click it. Indeed, analysis identified only one circumstance in 

which clicking the “refresh” button will affect the graphic interface. 

If the user has selected the download folder and clicked “unshare,” the folder will still be 

shared, but the green, checked circle that signals sharing will disappear, and it will not reappear. But if a user has seemingly “unshared” the download folder, then clicking 

“refresh” will—after the user re-expands the collapsed folder tree—make the green circle 

reappear on the download folder, indicating that it is being shared. 

So the behavior of the graphic interface may not be a bug: Someone who did understand 

its potentially misleading behavior may have worked hard to create this inconvenient, 

obscure Rube-Goldberg-like refresh-button to make the graphic interface report accurate 

information about the actual status of an “unshared” download folder. 

Programs like Morpheus, BearShare, and eDonkey also reveal another problem that 

arises when distributors implement coerced-sharing features that thwart attempts to stop

sharing the download folder: Such features can also thwart attempts to correct the effects 

of share-folder features. For example, Figure 14 shows a default installation of

BearShare automatically sharing a user’s “My Documents” folder because a previous 

installation of a prior version of the program had done so. 

But another problem is less evident in this screenshot: Neither the “Downloads” nor the 

“Folders” menu in BearShare will halt this behavior. BearShare’s “Downloads” submenu contains an undisclosed, librarying share-folder feature: It will never halt the 

sharing of any currently shared folder. Nor will BearShare’s share/unshare interface let a 

user stop sharing the download folder or any of its subfolders. Users must figure out for 

themselves that they must (1) access the BearShare share/unshare interface by finding the 

tiny button labeled “Folders,” on the “Library” view, (2) open the “Legends” submenu on 

the share/unshare interface to discover that solid red squares indicate that a folder is the 

download folder or a subfolder of the download folder, (3) exit from the share/unshare 

interface, (4) open the BearShare Setup menu; (5) open its “Downloads” submenu; (6) 

use the “Downloads” submenu to select a different folder to store downloads, (7) exit the 

BearShare setup menu, (8) re-open the BearShare share/unshare interface from the 

“Library” view, and (9) disable sharing of “My Documents” and its various subfolders. 

Not all programs have made it difficult for users to stop sharing the download folder. For 

example, recent versions of LimeWire still let users disable sharing of the “Save 

Directory” using the same method that disabled sharing in previous versions. LimeWire 

also seems to have implemented some other useful changes. In version 4.9 and above, 

LimeWire improved—somewhat—its librarying, recursive-sharing share-folder feature.71 

But when LimeWire 4.9 improved the share-folder feature, it also implemented a new 

“Individually-Shared-File” (ISF) feature. This ISF feature lets a user share a particular 

file without sharing the folder in which it is stored. The LimeWire User Manual 

describes ISF as a user-controlled, user-activated feature: “To share a file individually, 

right-click on a folder and select ‘Share New File.’” The Manual thus portrays the ISF 

feature as one that gives users unprecedented control over their sharing. 

44
But the Manual omits a key detail: By default, LimeWire itself will designate every file 

that a user downloads as an Individually Shared File. The ISF feature thus ensures that 

disabling sharing of the download folder no longer disables sharing of downloaded files. 

In versions of LimeWire after 4.8.1, users who want to stop sharing downloaded files 

must now disable sharing of the download folder, disable the ISF feature, and then 

disable the sharing of each downloaded file previously tagged by LimeWire as an ISF. In 

effect, ISF is a coerced-sharing feature that acts like a “backup” redistribution feature: In 

LimeWire 4.9 and above, users who once knew how to disable sharing of downloaded 

files at the folder level will now keep right on sharing.... 

In summary, four of the five programs studied here have deployed non-obvious, 

potentially misleading coerced-sharing features that can, however, be circumvented by 

sophisticated users who want to avoid the tedium and risk inherent in a copy-and-delete 

strategy. Such features appeared first in eDonkey and BearShare and were adopted later 

by Morpheus and LimeWire—during the period when the efficacy of redistribution, 

share-folder, and search-wizard features appears to have been waning. These coercedsharing features also have another effect: They render useless—or worse—almost all of 

those detailed, program-specific, step-by-step, screenshot-illustrated instructions that 

once described how to disable sharing. 

D. Next steps: Are search-wizard features poised to return? 

While this report has focused on the behavior of five popular filesharing programs, it has 

revealed patterns of behaviors that change over time: Coerced-sharing features are 

popular today, but users will eventually discover what they do and how to disable them. 

As that happens, new “technological features” that can “induce users to share” may arise. 

In late 2004, the authors of Usability and Privacy testified to the Federal Trade 

Commission about the problem of inadvertent sharing and criticized a less-well-known 

filesharing program, WarezP2P, for its aggressive search-wizard feature.72 A more recent 

version of WarezP2P still contains an aggressive search-wizard feature. It is triggered 

automatically when the program is installed. It does not disclose that identified folders 

will be shared recursively. It will, like the BearShare wizard, share all folders it identifies 

unless the user acts affirmatively to prevent this. Nevertheless, the following screenshot 

of the WarezP2P search-wizard’s results screen shows that it differs from previous 

wizards in one respect: 

45
Figure 23: Warez P2P 2.9.5.3040

The WarezP2P wizard now appears to specifically target folders containing audio files: In 

the screenshot shown above, it has targeted for recursive sharing a “My Music” folder 

containing hundreds of copyrighted audio files. One long-time user of Gnutella-based 

filesharing programs has reported that such features are now common, apparently among 

the less-popular client programs: “Gnutella applications frequently share the ‘My Music’ 

directory on Windows computers by default....”73

Search-wizards that target folders containing specific types of media files might reduce 

these features’ tendency to cause users to share existing sensitive files while preserving 

their tendency to cause users to upload existing infringing files. This sort of “targeted” 

search-wizard feature could become the next of the “technological features to induce 

users to share” to be widely deployed. 

IV. Conclusions and Implications. 

Public data on the behavior of filesharing programs reveals an array of “features” that 

could cause users to share files inadvertently. Some are obviously problematic: No 

wonder users upload files unintentionally if the interface that lets them select a folder to 

store downloaded files does not disclose that any folder selected will be shared, and 

shared recursively. Such circumstances make it relatively easy to answer the questions 

that this report seeks to address. 

46
A. Conclusions. 

This report seeks to answer two questions. First: Are there now, or have there been, 

features in popular filesharing programs that can cause users to share files 

unintentionally? Second: Do the totality of the circumstances suggest the need for further 

investigation to determine whether any particular distributor that deployed such a feature 

intended for it to dupe young or unsophisticated users into sharing files inadvertently?

The public data examined show that the answer to the first question is “Yes”: There are 

now, and there have been, features in popular filesharing programs that can cause users to 

share files unintentionally. These programs have contained, and some still do contain, 

features that could act like duping schemes—like “technological features” that “induce 

users to share” infringing files unintentionally. 

The public data examined also show that the answer to the second question is “Yes”: The 

circumstances surrounding the behavior and deployment of “technological features” that 

can “induce users to share” infringing files unintentionally do justify further investigation 

to determine whether distributors intended for these features to dupe young or 

unsophisticated users into sharing files inadvertently. 

Distributors have confronted new and unsophisticated users with an ever-changing array 

of redistribution, share-folder, search-wizard, partial-uninstall, and coerced-sharing 

features. These features were often implemented in ways that tended to obscure their 

effects. Some of these features have been implemented in ways that could confuse even 

experienced users; others in ways that are nearly inexplicable. Too often, 

implementations of these features became more aggressive after their potential effects on 

users were, or should have been, known to reasonable distributors of filesharing 

programs. 

Such conduct suggests the possibility of duping. The available data on users’ propensity 

to share files also suggests a potential motive: When sharing or uploading was a clearly 

voluntary behavior, few users chose to share files. Later, lawsuits against infringing 

users of filesharing programs appear to have decreased users’ already-limited propensity 

to share files voluntarily. Under such circumstances, it may be impossible to base a 

successful filesharing network entirely upon “voluntary cooperation among users”: 

Technological features that “induce users to share” files unintentionally may be 

indispensable. 

The ugly history of share-folder and search-wizard features further suggests that duping 

or another form of inducement may be critical to a viable filesharing network. Absent 

some pressing need, it is difficult to imagine why distributors of filesharing programs 

would have continued or begun to deploy search-wizard or share-folder features after 

mid-2003. These features were deployed while the Grokster litigation and various 

legislative proposals on filesharing piracy focused increasing attention on the distributors 

of these programs. They were deployed while distributors were telling Congress and 

federal agencies that inadvertent sharing was a mere “urban myth.” They were deployed 

47
while some distributors repeatedly informed agencies and Congress that they were 

complying with the following self-imposed obligation: 

[Our] software and associated user instructions shall conspicuously require 

the user to confirm the folder(s) containing the file material that the user 

wishes to make available to other users before making such material 

available, and shall be designed to reasonably prevent the inadvertent 

designation of the contents of the user’s entire hard drive (or other 

principal data repository) as material available to other users. 

Indeed, these share-folder and search-wizard features were deployed even after the 

predicted compromises of personal, national, and military security occurred or recurred. 

Distributors could, in theory, possess data that would suggest that their actions were the 

result of mistake or neglect. But these distributors were also making repeated 

representations about how promptly and responsibly they had responded to the problem 

of inadvertent sharing of sensitive files. It would be surprising if they had consistently 

failed to correlate their rhetoric against the reality of how their programs worked. For 

example, it is possible that the authors of BearShare’s Important Word and Important 

Privacy Notice simply did not know how their program actually operated. But if 

BearShare’s distributors did know that they were misrepresenting how their program

operated, then they probably had a good reason to do so. 

For these reasons, further investigation by entities that could require complete disclosure 

of non-public information about the behavior and evolution of filesharing programs may 

be warranted. Such efforts could show definitively whether the distributors of programs 

that deployed the features discussed in this report intended for these features to act as 

duping schemes—as “technological features to induce users to share.” 

Definitive answers to questions about the intent underlying the actions of distributors of

particular filesharing programs might clarify whether particular distributors would be 

subject to civil inducement liability under Grokster. They would also have broader 

significance. 

For example, a showing that features in filesharing programs were (or were not) intended 

to dupe users into sharing files unintentionally would show whether user education could 

resolve the problem of inadvertent filesharing. Granted, user education might be 

ineffective even if such features were mere errors in interface design: Consumers Union 

once warned that “[t]here may be no educating around a design flaw.”74 

But there can be no “educating around” a duping scheme: As users become “educated” 

about a scheme, the scheme should evolve and turn users’ “education” against them. If 

the “features” discussed in this report were deployed as duping schemes, then for users of 

filesharing programs, only one thing is certain: There is worse yet to come. 

Answers to questions about duping could also clarify the validity of claims that the 

networks created by filesharing programs show that properly designed code can inspire 

large groups of people to cooperate even when it would be irrational for any individual 

48
member of the group to do so: Some even suggest that filesharing reflects the emergence 

of a fundamental change in human nature—the evolution of Homo swappus. 

But this view of filesharing presumes that users share intentionally: “The fundamental 

premise of peer-to-peer systems is that individual peers voluntarily contribute resources 

to the system.”75 As Professor Wu has noted, those who advocate this view of filesharing 

might see the cartoon-bear mascot of BearShare as a fitting symbol of their cause: 

“There is little on the screen to suggest that a user is engaging in a morally 

ambiguous operation or is committing an act of theft. The friendly bear in 

BearShare is an icon of charismatic code.” 

Figure 24: "The Friendly Face of the BearShare Community"76

But the friendly face of this cartoon bear once concealed some ugly code. In some 4-

series versions of BearShare, that smiling bear deployed an increasingly less-obvious 

redistribution feature, an undisclosed, librarying, recursive-sharing share-folder feature, 

an aggressive search-wizard feature, a potentially dangerous partial-uninstall feature, and 

a potentially misleading coerced-sharing feature that sophisticated users can avoid. 

These features may have been deployed to trick the young and the unwary into uploading 

infringing files that culpable, revenue-generating leechers could download with little risk 

to themselves. 

If so, then BearShare would hardly reflect a step forward in human evolution. To the 

contrary, it would seem to reflect a regression to the law of the jungle—a return to a 

system that preys upon the young and the naive. 

Until questions about duping are resolved, potential users of 4-and-5-series versions of 

BearShare should beware the smiling “icon of charismatic code”: In these versions, that 

happy little cartoon bear has teeth. And he will bite. 

B. Implications. 

This report does not purport to draw conclusions about whether any given distributor of a 

particular filesharing program intended to deploy “technological features” in order to 

“induce users to share” files inadvertently. Nevertheless, for some groups of persons, 

significant implications follow from the conclusions drawn regardless of whether or how 

questions about any individual distributor’s intent are ultimately resolved. 

Government and Corporate IT-Security Managers: For anyone concerned about 

protecting the security of sensitive data or the security of computer networks, questions 

about whether features that can cause users to share files unintentionally were intended to 

49
do so are largely irrelevant. In either case—and as DHS has acknowledged—filesharing 

programs present a tripartite threat to the security of data and networks. 

• Filesharing programs can cause inadvertent sharing that can compromise entire 

networks: In networked environments, the effects of the “features” discussed 

above can be particularly devastating. For example, on some networks, a user 

who tries to store downloaded files in a folder like “Documents and Settings” can 

end up “sharing” all files created by all users of the network. Even home use of 

filesharing programs can compromise government or corporate networks: 

Usability and Privacy notes that if a home computer has a VPN connection to a 

corporate or governmental network, a user can inadvertently “share” the portion 

of the network available through the VPN connection. 

• Filesharing programs can infect computers or networks with malicious code: To 

avoid vicarious liability for pervasive infringing uses of their programs, 

distributors of filesharing programs stopped registering or uniquely identifying 

individual users of their programs. Distributors knew that this would encourage 

distributors of malicious code to use popular downloads as a means to 

compromise computers and networks: “As you would expect, when files often 

come from anonymous and uncertified sources, the risk of that file containing a 

virus greatly increases.”77 As a result, research by the security company 

TruSecure found that 45% of popular downloaded files concealed malicious 

code.78 

• Filesharing programs can contain vulnerabilities that hackers can exploit to steal 

sensitive data: DHS warns that filesharing programs “can result in network 

intrusions and the theft of sensitive data.... [F]ederal government organizations 

have discovered the presence of P2P software on compromised systems while 

investigating cyber intrusions.” McGill University warns that some filesharing 

programs are developed by “ragtag teams following ad hoc plans, resulting in 

barely functional, extremely buggy clients that are prone to security breaches.”79

All three of these risks increase because filesharing programs—unlike most others—often 

appear to be designed to go where they are not wanted and to evade the security measures 

that could exclude them. As one security expert warns, “Many of the finest computer 

minds in the world are continuously working to make the P2P programs evade the best 

detection schemes available.”80 

There will almost never be a legitimate business or governmental justification for 

employee use of filesharing programs. Nevertheless, preventing employees from using 

these programs on corporate or government networks can be both difficult and 

expensive.81 

Owners of Home Computers: People who store any type of sensitive data on their 

home computers—particularly computers to which children, teenagers, or college 

students might have access—confront circumstances similar to those faced by 

50
governmental or corporate IT managers. Unfortunately, owners of home computers face 

two additional challenges. 

First, owners of home computers will almost always lack the resources available to 

governmental or corporate IT managers. Second, home computers are often used by 

multiple persons, and the person who best understands which files are sensitive and 

where they are stored may not be the person who installs and runs a filesharing program. 

Indeed, whenever employees do work at home, government or corporate IT managers 

may find that these complications affect their interests as well. 

The critical challenge will be assessing the options available to owners of home

computers (or persons who contract with Internet-access providers) who want to prevent 

filesharing programs from being installed or used on their computers and networks. 

While software firewalls or routers can be configured so that only one person can grant 

Internet access to a program, this solution may prove impractical for most roommates or 

families. The Federal Trade Commission has done some initial investigation into other

filesharing-detection-or-prevention options available to owners of home computers. 

Further research and reporting by consumer-protection advocates might be useful. 

Users of Filesharing Programs: For users of filesharing programs, it is, again, largely 

irrelevant whether particular features in those programs were intended to—or simply 

can—cause some users to share infringing files inadvertently. In either case, many of the 

same implications follow. 

The research on uploading rates among users of filesharing programs suggests that users’ 

propensity to share files is affected, but not dictated, by the design of filesharing 

programs. The more than 100% increase in sharing reported between 2000 and 2001 

strongly suggests that program design can significantly affect users’ propensity to upload 

files. But the 500% plunge in sharing rates—to 15% of the user population— by 2004 

strongly suggests that users can, over time, overcome the effects of design. But the rise 

of coerced-sharing features suggests that as users overcome the effects of design, users’ 

past experiences can be turned against them. 

This suggests that users are neither unaffected nor enslaved by the design of filesharing 

programs. This may refute claims that distributors of filesharing programs do not 

“facilitate the exchange of files between users” or that users alone “select which files to 

share.”82 But it also seems to refute Professor Lessig’s claim that a “fundamental 

principle of bovinity” ensures that “it is as likely that the majority of people would resist 

[imperfect controls imposed through code] as it is that cows would resist wire fences.”83 

His “bovine account” of human nature asserts that most people are no more than witless 

cows. But, given time, information, and incentives, most users did resist some of the 

“technological barriers” to disabling sharing that filesharing programs tended to create. 

Unfortunately, while users of filesharing programs may have proven to be, over time, 

more competent—more human—than some thought, for users, the implications of 

features in filesharing programs that can cause users to share files inadvertently are 

almost universally bad. 

51
First, until distributors of filesharing programs eliminate all features in their programs

that can cause users to share files unintentionally—and stop adding new ones—

filesharing programs will be dangerous, use-at-your-own-risk propositions. While this 

report identifies some potential problems, the precautions taken to avoid confusing 

imperfect interface design with duping ensure that this report does not purport to identify 

all features in filesharing programs that could cause users to share files unintentionally: It 

is not a guide to “safe sharing.” 

Second, for now, users of filesharing programs who want to avoid inadvertent sharing are 

on their own. As Usability and Privacy noted, filesharing programs themselves often do 

a “poor job” of helping users avoid inadvertent sharing. The users’ guides and manuals 

for these programs are also often unhelpful, and some could be affirmatively misleading. 

Nor can users rely on the informal user forums associated with most programs: Posting 

questions on these forums about halting or restricting sharing may produce hostile 

“flame” responses, but little useful guidance. While users can search the Internet for 

instructions on disabling sharing in various programs, most are now dated, and some are 

inaccurate. Again, consumer-protection or public-interest advocates might assist by 

providing a regularly updated online guide to halting sharing in the more popular 

programs. Unfortunately, some technical analysis would be needed to confirm that 

features that seem to let users halt sharing actually do so. 

Third, users should assume that they can be held liable for infringing use of filesharing 

programs even if they share or upload infringing files unintentionally and even if they do 

as a result of features that were intended to dupe users. Direct liability for copyright 

infringement is a form of strict liability.84 And many users who upload copyrightprotected files inadvertently may do so negligently or recklessly: The features discussed 

above do not force users to share infringing files, and do they do not cause sharing that 

cannot be detected and corrected by a very alert, well-informed user. 

Moreover, while duping might cause high-volume uploading that triggers a copyrightenforcement lawsuit against a particular user, discovery will probably reveal other, more 

intentional, forms of infringement. As one commenter notes, “Virtually everyone who 

participates in one of the file-swapping networks is breaking the law in the process.”

85 

So regardless of whether a given user bears some measure of personal culpability for the 

sort of high-volume uploading of infringing files that can trigger an enforcement lawsuit, 

that user has probably also engaged in infringement not caused by duping. For example, 

uploading may have led rightsholders to sue one particular user of a filesharing program, 

but the courts ultimately held her liable for downloading infringing files.86 

Fourth, users should not expect rightsholders or courts to sympathize whenever a user 

claims that he or she was duped into becoming a high-volume uploader of infringing 

files. Duping schemes—or features that simply act like duping schemes—are dangerous 

because they make it difficult to distinguish those who acted unintentionally from

culpable wrongdoers who planned to “cry duping” if they were caught. For example, a 

culpable user of BearShare might use its share-folder feature to store downloaded files in 

“My Music” folder so he could, if caught, claim that he did not know that BearShare was 

52
recursively sharing all of the subfolders of “My Music” that stored thousands of audio 

files copied from lawfully purchased CDs. 

Fifth, users should recognize that the factors outlined above do not mean that users who 

have shared files unintentionally lack any form of legal redress. For example, one court 

adjudicating a lawsuit brought against a user of a filesharing program who claimed that 

she shared any allegedly infringing files inadvertently has noted that she could bring a 

state-law contribution or indemnity claim against the distributor of the filesharing 

program at issue.87 State consumer-protection laws may provide another means of 

redress. 

Finally, some defenders of filesharing may argue that the prevalence of “technological 

features” that can “induce users to share” infringing files makes it unfair for copyright 

holders to sue users of filesharing programs for infringement. They may thus argue that 

if distributors of filesharing programs have both encouraged users to infringe copyrights 

voluntarily and duped them into doing so involuntarily, then those distributors should be 

given them what they always wanted: A collective or compulsory license to distribute the 

copyrighted works targeted by their schemes. One could scarcely conceive of a better 

means to encourage future copyright piracy, fraud, and duping schemes. 

Distributors of filesharing programs: Distributors of filesharing programs may also

find that they should eliminate or fully disclose any features that could cause new or 

unsophisticated users of their programs to share files unintentionally—and do so 

regardless of whether or how questions about the intent underlying such features are 

resolved. 

Many distributors of filesharing programs have claimed that they want copyright 

enforcement to “leave the little guys alone”—to avoid targeting the young and 

unsophisticated users of filesharing programs who seem to be prevalent among the highvolume uploaders of infringing files. The data analyzed above strongly suggests that 

distributors of filesharing programs could make this aspiration a reality: If children and 

unsophisticated users shared hundreds of infringing files only when they clearly intended 

to do so, most would likely choose not to do so. The conclusion that Usability and 

Privacy drew in 2002 remains valid today: Eliminating features that can cause 

inadvertent sharing, and halting any continuing effects of previously deployed features, 

should be a “top priority” for responsible distributors of filesharing programs. 

Raw self-interest on the part of distributors may also dictate such a course. The 

intentional-inducement doctrine recognized in Grokster is unusual: Most civil laws 

impose liability for wrongful conduct without a showing of intent. This is true for most 

forms of direct or secondary liability for copyright infringement. It is also true for other 

forms of civil liability that could be triggered by “technological features” that “induce 

users to share” files inadvertently. 

For example, the distributor of a filesharing program that contains features that do cause 

users to share infringing files unintentionally could face direct or secondary liability for 

the resulting infringements absent any showing of intent. Direct liability for copyright 

53
infringement is joint and several: When an infringement occurs as the result of

consecutive wrongful acts by two parties, each is held fully liable. An infringing upload 

might occur only because (1) a distributor released a program that contained a not-soobvious redistribution feature, and (2) a user unaware of that feature intentionally 

downloaded an infringing file. In such a case, an infringing upload results from the 

combined effects of consecutive wrongful acts by the distributor and user of the program.

A similar result might follow under secondary-liability doctrines. If a program deploys a 

feature that its distributor knew or should have known would cause some users to upload 

infringing files inadvertently, then vicarious liability may attach: Such a distributor would 

have had the right and ability to control—indeed, to prevent—the infringing acts that the 

feature subsequently caused. 

Nor is civil liability for copyright infringement the only form of civil liability that might 

confront the distributor of a filesharing program containing “features” that cause users to 

share files unintentionally. Regardless of whether a file shared inadvertently is infringing 

or a sensitive personal file, the affected consumer incurs a significant risk of harm. Civil 

consumer-protection and tort laws impose forms of strict liability against distributors of

products—particularly if those products become, in effect, dangerous toys often used by 

children. Indeed, as noted above, at least one court has already noted that a user of a 

filesharing program who shares files inadvertently may have a cause of action for 

contribution against the distributor of the program. 

All of these factors suggest that any more attempts to deploy “technological features” that 

can “induce users to share” infringing files should be viewed with great skepticism. Six 

years ago, Free Riding on Gnutella questioned whether a viable filesharing network 

could be based upon “voluntary cooperation between users.” The public data analyzed 

here suggest that the events of the last six years may not answer this question. The events 

of the next few years probably will. 

54
APPENDIXES 

Appendix A: The Scope of This Report 

The scope of this report must accommodate both the scope of USPTO’s investigatory

authority, and the limitations of its investigatory powers. USPTO has an obligation to 

“advise Federal departments and agencies on matters of intellectual property policy in the 

United States and intellectual property protection in other countries.” 35 U.S.C. § 

2(b)(9). It may also “conduct ... studies ... regarding ... the effectiveness of intellectual 

property protection domestically and throughout the world.” Id. at § 2(b)(10). 

Consequently, USPTO can and should investigate whether duping schemes cause 

unnecessary conflicts between consumers and rightsholders and whether such schemes 

threaten the security of sensitive or classified government data. 

Nevertheless, USPTO is not a specialized investigatory or law-enforcement agency. 

USPTO does not have relevant legal authority to compel private parties to fully disclose 

all relevant information in their possession, custody, or control. Distributors of 

filesharing programs probably possess private data relevant to questions about whether 

they intended to dupe users into sharing files inadvertently. But USPTO cannot require 

them to disclose that information; nor can it ensure that any voluntary disclosures of such 

data are accurate or complete. As a practical matter, these limitations indicate that this 

report should pursue one of two alternative courses of analysis. 

On the one hand, this report could consider only public information or data. Public data 

can reveal much about the uploading related functions of filesharing programs and how 

they changed over time. But this approach has a disadvantage: Confining this 

investigation to publicly available data means that it could not fairly draw conclusions 

about whether the distributor of a particular filesharing program intended to dupe users of 

the program into uploading files unintentionally. Duping, like inducement generally, 

requires a showing of intent. Public data may provide strong evidence of intent: For 

example, data showing that a distributor of a filesharing program deployed features that a 

reasonable distributor would have known would cause users to share files unintentionally 

could permit a reasonable person to infer that this distributor intended to cause 

inadvertent sharing. Nevertheless, even in such a case, the distributor deploying such a 

feature might possess nonpublic data suggesting that it deployed such a feature 

mistakenly, negligently or recklessly. 

On the other hand, this report could seek to supplement public data with whatever 

nonpublic data distributors of the filesharing programs in question might choose to 

disclose voluntarily. This approach also has a disadvantage. It would be unlikely to 

reveal any presently nonpublic data indicative of duping: No entity should voluntarily 

disclose such data. Nor is this concern merely hypothetical: Distributors of filesharing 

programs have repeatedly disclosed some information about how the sharing-related 

functions of their programs should or do work to both committees of Congress and 

administrative agencies. Comparing the content of those representations against the 

actual behavior of distributors’ programs counsels against a repetition of such efforts. 

55
Consequently, this report will consider only public data or information about the sharing 

related functions of five popular search-and-download filesharing programs. It will thus 

attempt to answer two questions. 

• First, have distributors of these filesharing programs deployed features that could 

cause users to share infringing files inadvertently—features that could act like 

duping schemes?

• Second, could the circumstances surrounding the deployment of any such features 

warrant further investigation into whether those features were intended to dupe 

users into sharing infringing files inadvertently? 

Neither of these questions can be answered simply by determining whether filesharing 

programs have deployed, or do deploy, features that could cause users to share files 

inadvertently. Software-interface design is not a mature science: At present, users, 

software, and hardware can interact in ways that software designers and distributors do 

not intend, and, indeed, would rather avoid. 

This creates a risk of “false positives”: A program could contain a feature that causes 

users to share files unintentionally even though the program’s distributors did not intend

for it to do so. For example, reports indicate that for nearly a year, bugs in the LimeWire 

program allowed remote parties to access and download any file stored on a computer 

running LimeWire—regardless of whether that file was stored in a folder being “shared” 

by the program.

88 This was—and is—a serious security vulnerability that could cause 

users to unknowingly make files available to others. Nevertheless, no public data 

suggests that this flaw was intended to cause users of LimeWire to share files 

inadvertently. 

To reduce this potential risk of “false positives”—the risk that flawed interface design 

could be mistaken for potential duping—this report adopts five precautionary measures. 

Consequently, it will discuss a particular feature in a particular program only if it meets 

the following criteria: 

• First, the feature must have been widely deployed. It must be, or have been, 

present in multiple filesharing programs. 

• Second, the feature must have been widely deployed in popular filesharing 

programs. Scores of filesharing programs exist, so it would not be surprising if a 

few, marginal programs were irresponsibly designed. 

• Third, the feature must have been widely deployed in popular filesharing 

programs after its propensity to cause users to share files inadvertently was, or 

should have been, known to responsible, informed distributors of filesharing 

programs. Published research and reports, the representations of distributors of 

filesharing programs, and violations of the Code of Conduct drafted by the 

distributors of BearShare, eDonkey, LimeWire, and Morpheus could indicate 

56
actual or constructive knowledge of a particular feature’s propensity to cause 

inadvertent sharing. 

• Fourth, further protection against false positives can be provided by analyzing 

how a feature evolved over time: Very different implications might follow if 

implementations of a feature that had been shown to cause inadvertent sharing 

become more or less misleading over time. The former case might more strongly 

suggest possible duping. 

• Fifth, a feature that causes inadvertent sharing in a particular type of program

could have different effects in a program that had a different architecture. This 

report will thus focus only on those filesharing programs that provide users with 

search, uploading, and downloading capabilities functionally similar to those once 

provided by the filesharing program distributed by Napster, Inc.89 It will not 

discuss popular BitTorrent clients because of their significantly different

architecture and functionality. 

These precautions limit the potential for confusing error with possible duping, but at a 

cost: They ensure that this report does not purport to identify all features in the studied

programs that could cause users to share files inadvertently: For example, idiosyncratic or 

previously unknown features will not be covered. Unfortunately, the research conducted 

for this report suggests that such features may exist, at least in some programs. 

The answers to the two questions raised in this report were obtained by studying the 

uploading-related features of past and present versions of the programs examined. 

Versions of the programs examined were obtained, usually from the various websites that 

provide past and present versions of filesharing programs for downloading. Each 

program was then installed and operated on test computers that stored various .doc, .pdf, 

.mp3, .wma, and jpg. files in various subfolders of the “My Documents” folder. 

Screenshots of relevant behaviors were taken. The program was then uninstalled from

the test computer, and the configuration files left behind were deleted. When possible, 

experiments to confirm the behavior of particular versions of particular programs were

conducted repeatedly to ensure that the behavior in question could be replicated. 

Information about the sharing-related behavior of users of filesharing programs was 

obtained from published studies that collected relevant data. Computer-science 

researchers rely routinely on the results of these studies, and they provide a rare neutral 

source of systematically collected data on filesharing behavior. Nevertheless, they do not 

permit fine-grained analysis of users’ sharing behavior or how it changed over time.

90

Information was also obtained from searches of various filesharing networks conducted 

to determine whether users were still inadvertently sharing sensitive personal files. These 

searches were done to determine whether inadvertent sharing of sensitive files continued 

to be a problem in late 2005 and early 2006: They were not an attempt to systematically 

analyze or quantify the problem of inadvertent sharing. Their results suggest that the 

problem of inadvertent sharing of sensitive files continues and that it is more prevalent on 

the Gnutella filesharing network. 

57
Finally, the decision not to draw conclusions about the intent of any particular distributor 

of a given filesharing program is a conservative precaution. The ultimate goal of this 

report is to determine whether existing public data could warrant further investigation 

into the issue of intent: It thus reserves conclusions about the intent of particular 

distributors to those entities authorized to compel the truthful and complete disclosure of 

all relevant nonpublic information possessed or controlled by those distributors. 

Appendix B: Terms used in this report 

The intersection of copyright law and filesharing programs has spawned an array of 

acronyms, neologisms, and poorly defined terms. This report cannot avoid contributing 

to the growth of filesharing-related acronyms and neologisms, but it will try to avoid the 

use of poorly defined terms. 

Default settings, behavior, or installation: This report will sometimes refer to the 

“default” settings or behavior of the programs discussed. These references have an 

unusually narrow meaning: They refer to the way that a program would behave were it 

installed on a computer on which no filesharing program had been previously installed. 

The report also refers to a user performing a “default installation” of a program: This 

means that the user simply clicks “Next” or “OK” during each step in a program’s 

installation-and-setup process. The report’s discussion of partial-uninstall features

explains in more detail why default installations of the same program on different 

computers can “share” very different sets of files and folders. 

Distributors of filesharing programs: As used here, the term “distributors” does not 

encompass all persons or entities involved in the distribution of filesharing programs. 

Rather, it is a convenient way to refer more narrowly to the natural or legal persons that 

develop or make available to the public a particular filesharing program. For example, as 

the term is used here, Metamachines, Inc. is a distributor of eDonkey; Streamcast 

Networks, Inc. is a distributor of Morpheus; Free Peers, Inc. is a distributor of 

BearShare;91 LimeWire, LLC is a distributor of LimeWire; and Sharman Networks, Ltd. 

is a distributor of the KaZaA Media Desktop. 

The term “distributors of filesharing programs” does not encompass all entities that play 

some role in the distribution of filesharing programs. For example, it does not include 

entities that merely link to, host, or transmit over their own network copies of filesharing 

programs made available by third parties. It also excludes the individual users of a 

program who make copies of that program available for downloading by other users, or 

potential users, of the program in question. 

Downloaded files: This phrase refers to files that are stored on a computer running a 

filesharing program after those files were downloaded from a filesharing network. 

Download folder: This phrase refers to the folder on a computer running a filesharing 

program that will store copies of newly downloaded files. 

Filesharing Programs: A filesharing network consists of two basic components—a 

protocol and client programs that use the protocol to communicate: For example, 

58
LimeWire is a filesharing program that uses the Gnutella protocol. As used here, the 

phrase “filesharing program” may occasionally refer to those filesharing programs that 

provide users with uploading, search, and downloading capabilities similar to those once 

provided by the filesharing program distributed by Napster, Inc: As the Grokster courts 

put it, the phrase refers to those programs that “operate in a manner conceptually 

analogous to the Napster system...” or to a program that “functions as Napster did, 

except that it could be used to distribute more kinds of files, including copyrighted 

movies and software programs.” Usually, this phrase refers more specifically to the 

particular examples of such programs analyzed in this report. Those programs are 

Bearshare, eDonkey, KaZaA, LimeWire, and Morpheus. 

Calling these programs “filesharing programs” may offend parties on both sides of the 

debate about filesharing. Opponents of filesharing may object that this term obscures the 

fact that these programs and networks are actually “file-copying” and “file-distribution” 

systems: Users of these programs may “share” resources like bandwidth, but they do not 

“share” files in the way that the owner of a CD might share it by loaning it to a friend. 

The objection has merit, but the term “filesharing program” is widely used, and inventing 

another name for these programs and networks might cause more confusion than it would 

eliminate. 

On the other hand, proponents of filesharing may object that the programs discussed here 

create “decentralized,” “peer-to-peer” filesharing networks that may have unique 

advantages. Again, the objection has some merit, but on balance, it should be 

overlooked. The term “decentralized” has no clear meaning, and whatever meaning it 

does have appears to be more legal than technical.92 The term “peer-to-peer” may also be 

inappropriate: Reportedly, when the programs discussed here are operating in the default 

manner preferred by their distributors, a user can search for, locate, and download a file 

without interacting with another “peer” user or a computer owned by such a user.93 

While the term “peer-to-peer” has always been ambiguous, programs and networks that 

rely, by default, upon specialized search-index servers and dedicated, high-speed, 

terabyte-sized fileservers to store and transfer requested files may not be “peer-to-peer” 

in any meaningful sense. 

Inadvertent sharing: This phrase refers generally to situations in which individual users 

of filesharing programs have uploaded or “shared” particular files unintentionally. 

Inadvertent or unintentional sharing of infringing files is not synonymous with innocent 

or blameless sharing of such files: A user who did not intend to share infringing files may 

still have done so knowingly, recklessly, or negligently. For example, distributors of 

filesharing programs might well argue that because almost all such programs contain 

redistribution features that will cause users to share downloaded files by default, users 

who failed to educate themselves about a particular program’s redistribution feature were 

negligent or reckless. 

In general, reports of inadvertent sharing tend to involve users sharing one of two types 

of files unintentionally. Some reports involve users inadvertently sharing downloaded 

files—files that a user had downloaded from a filesharing network using the filesharing 

program in question. Other reports concern users inadvertently sharing existing files—

59
files that had not been downloaded with a filesharing program, but were being stored on a 

computer running a filesharing program. Inadvertent sharing of either type of file could 

cause users to share infringing files inadvertently. 

Infringing file: This term is a convenient way to refer to a file that contains or encodes a 

copyright-protected work that has been uploaded to or downloaded from a filesharing 

network without the authorization of the copyright owner. Its use is not intended to deny 

that there could be rare cases in which unauthorized uploading or downloading might be 

found not to infringe the exclusive rights of the holder of the copyrights in a work 

encoded in a given file. 

60
ENDNOTES

 

1

 John Borland, Covering tracks: New privacy hope for P2P, CNET NEWS.COM, Feb. 24, 2004

http://news.com.com/2100-1027-5164413.html); see also Press Release, Optisoft S.L., P2P Downloaders 

Go Anonymous with Blubster 2.5 (June 30, 2003) (announcing “the launch of Blubster 2.5 in the wake of

the latest litigious effort by the RIAA and MPAA.... Version 2.5 ... disassociate[s] file transfers from

specific users”), available at http://www.tinfoil.net/modules.php?name=News&file=article&sid=703; New 

wave of secret file sharing breaks over Web, THE INQUIRER, May 10, 2004 (“A spokesperson for Optisoft 

said that ... the RIAA would be forced to do a mass action against every user in the network, and would be 

unable to identify each person’s liability.”), http://www.theinquirer.net/default.aspx?article=15808.

2

 United States v. Gooding, 25 U.S. 460, 469 (1827) (Story, J.); see also, e.g., United States v. Giles, 

300 U.S. 41, 49 (1937) (holding the defendant liable for causing an “innocent intermediary” to make false 

entries in the accounts of a bank); U.S. v. Bryan, 483 F.2d 88 (3d Cir. 1973) (“A crime may be performed

through an innocent dupe, with the essential element of criminal intent residing in another person.”); 

Baruch Weiss, What Were They Thinking: The Mental States of the Aider and Abettor and the Causer

under Federal Law, 70 FORD. L. REV. 1341, 1354 (2002) (using the term “causer” to distinguish an abettor 

who has an illegal act performed by “an innocent dupe”). 

3

 Metro-Goldwyn-Mayer Studios, Inc. v. Grokster, Ltd., 2006 U.S. Dist. LEXIS 73714 (C.D. Cal. 

Sept. 27, 2006). 

4

 Krishna Gummadi et al., Measurement, Modeling, and Analysis of a Peer-to-Peer File-Sharing

Workload, PROC. 19TH SYMP. ON OPERATING SYSTEM PRINCIPLES (Oct. 2003) (showing that the volume of

data requested by a given KaZaA client declines sharply after its first week of existence and decreases

steadily thereafter and concluding that “new clients generate most of the load in Kazaa”); cf. Stephan 

Sariou et al., An Analysis of Internet Content Delivery Systems, PROC. 5TH INT’L SYMP. ON OPERATING

SYSTEM DESIGN AND IMPLEMENTATION (2002) (“[A] very small number of Kazaa clients have a huge

overall bandwidth impact.”). 

5

 Chad Silver, Censure the Tree for Its Rotten Apple: Attributing Liability to Parents for the 

Copyright Infringement of Their Minor Children, 3 CARDOZO PUB. L. POL’Y & ETHICS J. 977, 978 & n.6

(2006) (“According to ‘some estimates, teenagers make up half of the of the ... people who use [online] 

file-swapping services’ to illegally trade music.”) (citation omitted); PEW INTERNET & AMERICAN LIFE

PROJECT, TEEN CONTENT CREATORS AND CONSUMERS iii, 10 (2005) (“51% of online teens say they 

download music files”); PEW INTERNET & AMERICAN LIFE PROJECT, THE MUSIC DOWNLOADING DELUGE 2 

(2001) (“53% of youth between the ages of 12 and 17 have also downloaded music files”); see also Jane

Musgrave, Music Downloads Hit Sour Note for Sued Ordinary Folks, PALM BEACH POST, June 26, 2006, at 

1A (“Not surprisingly, many of the [RIAA] lawsuits are against parents who say they had no idea their 

teenage children were downloading music illegally.”); Memorandum from the Electronic Frontier 

Foundation to Defense counsel in RIAA and MPAA individual file sharing suits, Parental Liability for 

Copyright Infringement by Minor Children (Nov. 1, 2005) (“In many of these instances, suit has been

brought against either a minor child or her parents based on the allegedly infringing activities of the 

child....”), http://www.eff.org/IP/P2P/Parent_Liability_Nov_2005.pdf.

6

 See Tim Wu, When Code Isn’t Law, 89 VA. L. REV. 679, 685 (2003); Jane C. Ginsburg, Putting 

Cars on the “Information Superhighway”: Authors, Exploiters, and Copyright in Cyberspace, 95 COLUM. 

L. REV. 1466, 1488 (1995); see also 17 U.S.C. at § 512(b)-(d) (creating limitations on the potential liability 

of internet-service-providers who, inter alia, comply with an expeditious notice-and-takedown process that 

minimizes the need for copyright enforcement against end-users). 

7

 FRED VON LOHMANN, ELECTRONIC FRONTIER FOUNDATION, IAAL: PEER-TO-PEER FILE SHARING 

AND COPYRIGHT LAW AFTER NAPSTER (2006), http://www.eff.org/IP/P2P/p2p_copyright_wp_v5.pdf. See 

61
 

also, Tim Wu, When Code Isn’t Law, 89 VA. L. REV. 679, 731 (2003) (“The design [of Gnutella] was an

intentional effort to create a filesharing protocol that could avoid a lawsuit.”); id. at 735 (“KaZaA ...

maintains no power to ‘shut down’ the network.”). 

8

 ELECTRONIC FRONTIER FOUNDATION, RIAA V. THE PEOPLE: TWO YEARS LATER 2, 6-7 (2005), 

http://www.eff.org/IP/P2P/RIAAatTWO_FINAL.pdf. Previously, EFF had argued that RIAA’s failure to

sue individual uploaders of infringing files proved that RIAA’s lawsuits against distributors of filesharing

programs were intended to control technology rather than to deter copyright piracy. See, e.g., Declan 

McCullough, End of an Era for File-Sharing Chic?, CNET NEWS.COM, Aug. 25, 2003 (reporting that EFF 

had argued “that P2P users ‘are the ones who are the alleged pirates. If this fight were really about

stopping piracy, you would have expected some pirate to actually be sued.’”), http://news.com.com/2010-

1071_3-5067473.html. 

9

 Bruce Byfield, RIAA conducting “reign of terror,” lawyer says, NEWSFORGE, July 20, 2006, 

http://trends.newsforge.com/article.pl?sid=06/07/20/1651223. 

10 P2P United, Peer-to-Peer Trade Group to RIAA Bullies: Come Out and Fight Us If You Want, 

But Leave the Little Guys Alone!!! (Sept. 10, 2003), http://www.bearshare.com/press/riaabullies.htm.

11 While this report was being prepared, Free Peers, Inc., the distributor of the 4-and-5-series

versions of BearShare analyzed in this report, reportedly settled litigation brought by copyright holders and 

sold the rights to BearShare to another entity that has, or may, re-launch BearShare as an licensed

filesharing service. This report has not analyzed any “re-launched” versions of BearShare; its conclusions 

about potentially problematic sharing-related features in older versions of BearShare do not imply that such

features would continue to exist or would have similar effects upon users of a licensed filesharing service. 

12 See, e.g., Nicolas Christin et al., Content Availability, Pollution and Poisoning in File Sharing 

Peer-to-Peer Networks, PROC. OF THE 6TH ACM CONF. ON ELECTRONIC COM, 70 (2005) (“in both

FastTrack and Gnutella, leaf nodes are promoted to hubs by the software client, and generally unbeknownst

to the user”); cf. Krishna Gummadi et al., Measurement, Modeling, and Analysis of a Peer-to-Peer FileSharing Workload, n.3, PROC. 19TH SYMP. ON OPERATING SYSTEM PRINCIPLES (Oct. 2003) (“P2P software

is often designed to make it difficult to close the program once it starts, ‘fooling’ users into making their 

clients more available than they intended.”). 

13 Lior Jacob Strahilevitz, Charismatic Code, Social Norms, and the Emergence of Cooperation on

the File-Swapping Networks, 89 VA. L. REV. 505, 549-50 (May 2003); cf. Tim Wu, When Code Isn’t Law, 

89 VA. L. REV. 679, 724 (2003) (arguing that the design of filesharing programs “brilliantly” exploits 

ambiguities about “whether home, non-commercial copying is ‘wrong’”). 

14 Eytan Adar & Bernardo A. Huberman, Free Riding on Gnutella, 5 FIRST MONDAY iss. 10, Oct. 

2000, http://www.firstmonday.dk/issues/issue5_10/adar/; see also infra note 66 (reporting that Free Riding 

has been cited over 100 times in computer-science research papers); cf. Tim Wu, When Code Isn’t Law, 89 

VA. L. REV. 679, 686 (2003) (“etiquette among users must be engineered or ... induced with ‘charismatic

code’”).

15 See Lior Jacob Strahilevitz, Charismatic Code, Social Norms, and the Emergence of Cooperation 

on the File-Swapping Networks, 89 VA. L. REV. 505, 526 (May 2003); Compare MusicLabs, LLC, 

Gnutella Good Citizen Tips, (“[A] good citizen will always shares files; the more the better.”), 

http://www.bearshare.com/help/citizen.htm (last visited Sept. 19, 2006), with MusicLabs, LLC, Press FAQ, 

(“Gnutella 0.56, was good for its time but should never be used on the network since it does not have ‘good

citizen’ features.”), http://www.bearshare.com/help/faqpress.htm (last visited Sept. 19, 2006). 

62
 

16 Eytan Adar & Bernardo A. Huberman, Free Riding on Gnutella, 5 FIRST MONDAY iss. 10, Oct. 

2000, http://www.firstmonday.dk/issues/issue5_10/adar/; Michael Feldman & John Chuang, Overcoming 

Free-Riding Behavior in Peer-to-Peer Systems, ACM SIGECOM EXCHANGES, vol. 5, iss. 4, 42 (July 2005). 

Professor Wu has argued that “the filesharer’s comparative advantage lay in designing code to avoid 

copyright law.” Tim Wu, When Code Isn’t Law, 89 VA. L. REV. 679, 740 (2003). The research cited

above shows that this “advantage” comes at a cost: Designs that tend to facilitate the avoidance of 

copyright law also tend to discourage the sharing of files. Cf. id. at 717 (“P2P design shows that avoiding

copyright requires important deviations from the optimal design for speed, control, and usability”). 

17 Kevin Faaborg, Losing the Long Tail, LimeWire Blog (July 13, 2006) at 

www.limewire.org/blog/?cat=29. LimeWire levels a similar accusation at BitTorrent: “BitTorrent is 

horrible at rare stuff! As soon as a files becomes rare, it looses [sic] seeders and dies.” Id. 

18 See Kristyn Maslog-Lewis, Sharman Exec Calls Child Porn Unstoppable, CNET NEWS.COM, 

Dec. 9, 2004, http://news.com.com/Sharman+exec+calls+child+porn+unstoppable/2100-1027_3-

5486666.html; Richard Wallace, In Memory of Jessica (Mar. 23, 2005) (describing how a pedophile would

use inadvertently shared data to abduct and murder a child and noting that “[a]ll names are fictitious, 

however the information in this scenario is based on my research of inadvertent file sharing via P2P 

networks”), http://www.seewhatyoushare.com (available at http://web.archive.org/web/200503 

30014425/http://www.seewhatyoushare.com/).

19 Similar conclusions are drawn in almost all subsequent research on filesharing networks. See, 

e.g., Michael Feldman & John Chuang, Overcoming Free-Riding Behavior in Peer-to-Peer Systems, ACM

SIGECOM EXCHANGES, vol. 5, iss. 4, 41 (July 2005) (“P2P system performance is highly dependent upon

the amount of voluntary resource contribution from the individual nodes”); id. at 43 (“We find that if

societal generosity is below a certain threshold, then there are too many selfish rascals around and the 

system collapses”); id. at 47 (“Overcoming free-riding behavior is central to the performance and

robustness of P2P systems.”); id. at 47 (“[U]ser behavior can have potentially devastating effects on P2P

system performance, and so must be explicitly accounted for in P2P system design.”); see also Stephan 

Schosser et al., Incentives Engineering for Structured P2P Systems—A Feasibility Demonstration Using

Economic Experiments, PROC. 7TH ACM CONF. ON ELEC. COM. (2006) (free riding “can even lead to a 

collapse of these systems”); Robson Santos et al., Accurate Autonomous Accounting in Peer-to-Peer Grids,

PROC. 3D INT’L WORKSHOP ON MIDDLEWARE FOR GRID COMPUTING (2005) (free riding can “collapse” a 

P2P network); Emmanuelle Anceaume et al., Incentive for P2P Fair Resource Sharing, PROC. 2ND INT’L 

WORKSHOP ON PEER-TO-PEER SYSTEMS, 139 (2003) (free riding can lead to “system collapse”); Lakshmish

Ramaswamy & Ling Liu, Free Riding: A New Challenge for Peer-to-Peer File Sharing Systems, PROC. OF 

THE 36TH HICSS CONF. (2003) (discussing “the seriousness of the free riding problem and the need to

tackle this growing menace”). Nevertheless, Free Riding remains unusual among the published research on

filesharing because it acknowledges more explicitly that distributors and developers of filesharing 

programs—not merely users—might behave strategically, and in ways that are less than admirable. 

20 See Janelle Brown, The Gnutella Paradox, SALON, Sept. 29, 2000,

http://archive.salon.com/tech/feature/2000/09/29/gnutella_paradox/print/html; see also id. (reporting that 

Gnutella would not scale unless it were to “include a system ‘default’ that forces all users to share, much 

like Napster”). 

21 Stepan Sariou, P. Krishna Gummadi & Steven D. Gribble, Measuring and Analyzing the 

Characteristics of Napster and Gnutella Hosts, MULTIMEDIA SYSTEMS, vol. 9, iss. 2, 170 (2003). This 

study still concludes that more than 50% of available files were shared by 7% of users; it thus re-affirmed

the conclusion that “Gnutella has an inherently large percentage of free-riders. Id. 

22 Lior Jacob Strahilevitz, Charismatic Code, Social Norms, and the Emergence of Cooperation on

the File-Swapping Networks, 89 VA. L. REV. 505, 526-27 (May 2003).

63
 

23 Letter from Sharman Networks, Ltd., to Senators Graham, Feinstein, Durbin, Smith, Cornyn and 

Boxer, 4 (Dec. 15, 2003) (on file with author); Universal Music Australia Pty Ltd v. Sharman License

Holdings Ltd, 2005 FCA 1242, slip op. at 55 (Fed. Ct. of Australia Sept. 5, 2005) (the CEO of Altnet 

concludes that “p2p exists by virtue of this feature being turned on”); see also The Future of Peer-to-Peer

(P2P) Technology: Hearing Before the Subcomm. on Competition, Foreign Commerce, and Infrastructure 

of the Senate Comm. on Commerce, Science, & Transportation, 108th Cong. (June 23, 2004) (written 

testimony of Michael Weiss) (“[R]equiring a change in ‘sharing’ default[s]” would “hobbl[e]” Morpheus.);

Nicolas Christin et al., Content Availability, Pollution and Poisoning in File Sharing Peer-to-Peer 

Networks, PROC. OF THE 6TH ACM CONF. ON ELECTRONIC. COM. 68, 72 (2005) (“Content replication is a 

direct result of propagation, and is perhaps the most important reason behind the success of peer-to-peer 

networks.”) 

24 Nicolas Christin et al., Content Availability, Pollution and Poisoning in File Sharing Peer-to-Peer 

Networks, PROC. OF THE 6TH ACM CONF. ON ELECTRONIC. COM., 68 (2005); see also id. at 74 (concluding 

that redistribution features are also “an efficient antidote” to the spoofing efforts of rightsholders). 

25 Lior Jacob Strahilevitz, Charismatic Code, Social Norms, and the Emergence of Cooperation on

the File-Swapping Networks, 89 VA. L. REV. 505, 526 (May 2003); cf. Tim Wu, When Code Isn’t Law, 89 

VA. L. REV. 679, 735 (2003) (“[KaZaA] promotes selfless behavior by sharing user files without telling the 

user.”). 

26 Brief of Amicus Curiae Reviewing Issues of Fact and Law at 12, 44, 49, Capitol Records, Inc. v. 

Alaujan, No. 1:03-CV-11661-NG (Dist. Mass. May 24, 2004); see also id. at 2 (noting that their brief was 

filed not to advocate for a particular side, but “to help the Court strike a fair balance among legitimate and

often competing interests in this matter”); see also id. at 10 (“Disabling the default file-sharing features in

KaZaA is a complicated process due to an intricate series of steps within the software itself. In addition,

the available resources that detail how to disable file sharing are often inconsistent or provide incomplete 

instructions.”); id. at 12 (“The varying sources of instructions on disabling file sharing and the 

inconsistencies among them demonstrate that it can be extremely difficult for a non-expert computer user to

shut down their file-sharing capability.”); id. at 10-11 (quoting a college administrator who warns, “many

people are unaware, that if file-sharing is on when they download a music or movie file, they automatically

turn their computer into a server, providing those files to others across the Internet”) (citation omitted); id. 

at 44 (arguing that “technological barriers” can prevent a user from controlling or supervising “infringing

conduct of which he neither approves nor is aware”); id. at 49 (“[I]t may be unclear to an unsophisticated

party that by simply downloading the service and failing to take certain additional affirmative action, the 

user is making certain files on his computer available to be uploaded by other users.”); id. at 45 (“[S]ome

may be able to point to the complexity of KaZaA’s ... disabling functions to support a finding that there

was no awareness or intent to permit uploading.”).

27 Matthew Sag, Piracy: Twelve Year-Olds, Grandmothers, and Other Good Targets for the 

Recording Industry’s File Sharing Litigation, 4 NW. J. TECH. & INTELL. PROP. 133, 148 (2006).

28 RIAA Sues another Grandmother, P2PNET.NET NEWS, Aug. 2, 2006, http://p2pnet.net/story/9501;

see also Privacy and Piracy: The Paradox of Illegal File Sharing on Peer-to-Peer Networks and the Impact

of Technology on the Entertainment Industry: Hearing Before the Senate Permanent Subcomm. on

Investigations of the Comm. On Gov’tal Affairs, 108th Cong. 132-33 (Sept. 30, 2003) (statement of 

Lorraine Sullivan); Bob Mehr, Gnat, Meet Cannon, THE METER, Feb. 4, 2005 (reporting that Cecilia 

Gonzalez did not realize that she was sharing downloaded files),

http://www.chicagoreader.com/TheMeter/050204.html. 

29 Privacy and Piracy: The Paradox of Illegal File Sharing on Peer-to-Peer Networks and the 

Impact of Technology on the Entertainment Industry: Hearing Before the Senate Permanent Subcomm. on

64
 

Investigations of the Comm. On Governmental Affairs, 108th Cong. 132-33 (Sept. 30, 2003) (statement of

Lorraine Sullivan). 

30 P2P United, Member Code of Conduct (Sept. 29, 2003), 

http://wiki.morpheus.com/~p2punited/code.php. 

31 Filesharing programs may also disclose information about redistribution features in End-User

License Agreements (“EULAs”) or “click here for more information” hyperlinks. Absent evidence that

significant numbers of new users actually read EULAs or click on such hyperlinks, such disclosures would 

be, as a practical matter, irrelevant. See, e.g., Ben Edelman, Comparison of Unwanted Software Installed 

by P2P Programs (March 7, 2005) (explaining the engineered difficulties involved in reading the KaZaA or

eDonkey EULAs), http://www.benedelman.org/spyware/p2p. 

32 LimeWire is the exception, but its distributors deserve no credit for their “disclosures.” LimeWire

discloses its redistribution feature during its setup process, but it does so through an interface that does not 

allow the user to disable redistribution. Moreover, this interface also lets the user select a different folder

to store downloaded files—but without warning the user that all subfolders of this folder will be shared

recursively. This interface is, in effect, an undisclosed, recursive-sharing share-folder feature.

33 Atip Asvanund, Sarvesh Bagla, Munjal H. Kapadia, Ramayya Krishnan, Michael D. Smith, Rahul

Telang, Intelligent Club Management in Peer-to-Peer Networks, WORKSHOP ON ECON. OF PEER-TO-PEER 

SYSTEMS (2003), http://www2.sims.berkeley.edu/research/conferences/p2pecon/papers/s6-asvanund.pdf. 

34 See, e.g., Lakshmish Ramaswamy & Ling Liu, Free Riding: A New Challenge for Peer-to-Peer 

File Sharing Systems, PROC. OF THE 36TH HICSS CONF. (2003) (explaining why a “replication enforcement 

scheme doesn’t address the more serious problem of the system not getting new files and becoming 

stagnant”); see also Krishna Gummadi et al., Measurement, Modeling, and Analysis of a Peer-to-Peer FileSharing Workload, PROC. 19TH SYMP. ON OPERATING SYSTEM PRINCIPLES 314, 320 (Oct. 2003) (“[T]he 

primary object dynamic in the Kazaa workload is the arrival of entirely new objects.”); id. at 324

(“Without new popular [files] to choose from, existing clients quickly exhaust the set of popular objects.”).

35 As the term “ share-folder feature” is used here, a program may have no “ share-folder feature” 

even if it has a feature or interface that lets users store downloaded files in a folder other than the default 

download folder. As long as the interface has little potential to mislead the user into sharing files in a 

selected folder unintentionally, it is not a “ share-folder feature” for purposes of this report. For example, 

both LimeWire 2.0.4 and KaZaA 2.5 contained features that let users store downloaded files in other 

folders, but these features were accompanied by disclosures that— while not perfect—distinguish these 

features from the “share-folder features” discussed in this report.

36 Supra, note 7; see also Tim Wu, When Code Isn’t Law, 89 VA. L. REV. 679, 730 (2003) (“Napster 

taught peer network designers that both lack of control and general functionality had to be comprehensive 

and credible to avoid contributory liability.”) (emphasis added). 

37 See AMERICA ONLINE, INC. & NATIONAL CYBER SECURITY ALLIANCE, AOL/NCSA ONLINE 

SAFETY STUDY (2005) (finding that 68% of respondents reported keeping sensitive data on their home 

computer and 74% used the computer for banking, stock trading, or reviewing medical data),

http://www.staysafeonline.info/pdf/safety_study_2005.pdf. 

38 Worse yet, the potential for inadvertent sharing of sensitive files increases if users follow ordinary 

data-management practices. Users are now urged to store the data files created and used by their 

application programs in a single folder “tree” or hierarchy: In computers using the Windows operating

system, the base of this folder hierarchy is usually the “My Documents” folder, or the “Documents and 

Settings” folder. See, e.g., ED BOTT & CARL SEICHERT, WINDOWS XP INSIDE OUT 261-62 (2001). This 

65
 

strategy makes it easier for users to locate, backup, and transfer data files. But this strategy means that 

disastrous breaches of privacy and security can result from inadvertent “sharing”—particularly recursive 

sharing—of existing files and folders, such as a user’s “My Documents” folder. 

39 Nathaniel S. Good & Aaron Krekelberg, Usability and Privacy: A Study of KaZaA P2P FileSharing (2002) reprinted in PROC. OF THE SIGCHI CONF. ON HUM. FACTORS IN COMPUTING SYSTEMS, vol. 

5, iss. 1, 137-144. This study is now considered one of the “classics” of research on the interaction 

between usability and security. See generally, SECURITY AND USABILITY: DESIGNING SECURE SYSTEMS

THAT PEOPLE CAN USE (Lorrie Cranor & Simson Garfinkel eds., 2005). 

40 Usability and Privacy also identified other aspects of the KaZaA program that tended to confuse 

users, though they did not, in themselves, cause users to share files inadvertently. These included the 

media library view, and the fact that folders shared by the KaZaA share-folder feature were not labeled as

shared in KaZaA’s Shared Folder list. While these features may make it more difficult for users to detect 

inadvertent sharing, neither will, in itself, cause inadvertent sharing. Consequently, neither feature will be

discussed in detail here. 

41 See, e.g., Staff Report of the United States House of Representatives Comm. on Gov’t Reform, 

File-Sharing Programs and Peer-to-Peer Networks: Privacy and Security Risks, 1 (May 2003) 

(“Committee investigators found ... tax returns, medical records, attorney-client communications, and

personal correspondence from P2P users [and] ... at least 2,500 Microsoft Money backup files, which store

the user’s personal financial records, available for download.”) reprinted in Overexposed: The Threat to 

Privacy and Security on Filesharing Networks: Hearing Before the United States House of Representatives 

Comm. on Gov’t Reform, 108th Cong. 127 (May 15, 2003); see also Nicolas Christin et al., Content 

Availability, Pollution and Poisoning in File Sharing Peer-to-Peer Networks, PROC. OF THE 6TH ACM

CONF. ON ELECTRONIC. COM. 68, 77 (2005) (“[S]tudies of user behavior show that a vast number of users 

are vastly unaware of the files they share.”)(citation omitted). 

42 The Dark Side of a Bright Idea: Could Personal and National Security Risks Compromise the 

Potential of P2P File-Sharing Network?: Hearing Before the Senate Comm. on the Judiciary, 108th Cong. 

8 (June 17, 2003) (statement of Sen. Orrin G. Hatch); see also id. at 67 (statement of Sen. Patrick Leahy); 

id. at 2 (statement of Sen. Dianne Feinstein). 

43 Id. at 45 (comments on security by Phil Morle, Director of Technology for Sharman Networks, 

Ltd.); accord id. at 73 (written statement of Alan Morris, Executive Vice President for Sharman Networks, 

Ltd.). 

44 P2P United, Member Code of Conduct (Sept. 29, 2003), 

http://wiki.morpheus.com/~p2punited/code.php. 

45 The Future of Peer-to-Peer (P2P) Technology, A Hearing before the Senate Subcommittee on

Competition, Foreign Commerce and Infrastructure of the Senate Committee on Commerce, Science &

Transportation (June 23, 2004) (testimony of Mr. Michael Weiss on behalf of the distributors of

BearShare, eDonkey, and Morpheus) at http://commerce.senate.gov/hearings/testimony.cfm?id=

1247&wit_id=3577. 

46 P2P United, P2P United FAQ, http://wiki.morpheus.com/~p2punited/faq.php (last visited Sept. 18, 

2006); see also LimeWire, Frequently Asked Questions (“Q: Are there security risks associated with using 

LimeWire? A: As long as you don’t share your entire hard drive, you shouldn’t encounter any significant 

security risks using Gnutella.”), http://www.limewire.org/wiki/index.php?title=Frequently_Asked_ 

Questions#sec1 (last visited Sept. 18, 2006). 

66
 

47 Comments of P2P United at 12, Peer-to-Peer File-Sharing Technology: Consumer Protection and 

Competition Issues, A Workshop Before the Federal Trade Commission (Jan. 18, 2005) available at

http://www.ftc.gov/os/comments/p2pfileshare/index.htm (quoting the Senate testimony of Streamcast CEO 

Michael Weiss); id.at 4 (asserting that Morpheus, BearShare, and eDonkey “are in full compliance with the 

Code, which directly addresses ... user data security”); id.at 10 (“[W]e are confident that the following

characterizations of ‘myth’ and fact will prove accurate.”); see also Privacy and Piracy: The Paradox of 

Illegal File Sharing on Peer-to-Peer Networks and the Impact of Technology on the Entertainment

Industry: Hearing Before the Senate Permanent Subcomm. on Investigations of the Comm. On Gov’t 

Affairs, 108th Cong. 109 (Sept. 30, 2003) (statement of Alan Morris, Executive Vice President of Sharman 

Networks, Ltd.) (testifying that copyright holders “have attempted to smear the P2P industry and scare 

consumers by making false and misleading claims over bogus security issues and alleged privacy

concerns”); Lisa Rein, Interview with LimeWire COO Greg Bildson, OPENP2P.COM, Nov. 14, 2003 

(“[T]he RIAA is talking about ... homeland security and identity theft and all of these things that are really 

minor concerns, with regard to P2P.”), www.openp2p.com/pub/a/p2p/2003/11/14/limewire.html. 

48 File Sharers, Beware!, CBS EVENING NEWS, May 5, 2005, 

http://www.cbsnews.com/stories/2005/05/03/eveningnews/main692765.shtml; see also id. (reporting that 

one vigilant user warned 120 people that they were inadvertently sharing financial documents); see also

Brian Krebs, Extreme File Sharing, WASHINGTONPOST.COM , Oct. 17, 2005 (reporting that when the author

searched for inadvertently shared files on LimeWire, “I quickly found what I was looking for, and then

some: dozens of entries for tax and payroll records, medical records, bank statements, and what appeared to 

be company books” and users sharing email “inboxes and archives”), http://blog.washingtonpost.com/ 

securityfix/2005/10/extreme_file_sharing_1.html. 

49 Richard Wallace, Is a Free Song Worth Your Identity? (March 12, 2005) (“I know for a fact that 

identity theft is occurring via P2P.... I have personally called three different individuals where it was 

obvious that they were unknowingly sharing information.... All three responded with, thank you very, 

very much.... Someone has been using my credit cards and the bank’s fraud detection system picked up on

it; now I know how they got my info!”), http://www.seewhatyoushare.com/2005/03/is-free-song-worthyour-identity.html (available at http://web.archive.org/web/20050301025717/http:// 

www.seewhatyoushare.com/). 

50 BLUE SECURITY, P2P EXPLOITED TO SPAM MILLIONS OF USERS 1 (2005) (cited in Gregg Keizer, 

Spammers Mining P-To-P for Addresses, INFORMATIONWEEK, April 19, 2005, 

http://www.informationweek.com/story/showArticle.jhtml?articleID=160903121). 

51 Chris Preimesberger, Cyber-criminals Use P2P Tools for Identity Theft, Security Analyst Warns, 

EWEEK, June 23, 2006, http://www.eweek.com/article2/0,1895,1980963,00.asp; see also PAUL PICCARD ET 

AL., SECURING IM AND P2P APPLICATIONS FOR THE ENTERPRISE, 231 (Marcus Sachs eds., 2005) (“A quick

scan of the P2P networks turns up a treasure trove of files . . . including financial information, passwords, 

and files that you might not want to see the light of day.”). 

52 DEPARTMENT OF HOMELAND SECURITY, UNAUTHORIZED PEER TO PEER (P2P) PROGRAMS ON 

GOVERNMENT COMPUTERS (2005), http://www.dhs.gov/interweb/assetlibrary/IAIP_UnauthorizedP2P 

ProgramsGovtComp_041905.pdf; see also Eric Horton, Downloading Shared Files Threatens Security, 

ARMY NEWS SERVICE, April 22, 2004 (“Over a two-month period at the end of [2003], government

organizations identified more than 420 suspected P2P sessions on Army systems in more than 30 locations

around the globe.”), http://www4.army.mil/ocpa/read.php?story_id_key=5878. 

53 Compare Nathaniel S. Good & Aaron Krekelberg, Usability and Privacy: A Study of KaZaA P2P 

File-Sharing (2002) reprinted in PROC. OF THE SIGCHI CONF. ON HUM. FACTORS IN COMPUTING SYSTEMS, 

vol. 5, iss. 1, 138 (2003) (finding inadvertently shared email inbox files on Gnutella “yet in fewer numbers 

than KaZaA”), with Thomas Mennecke, What’s in Your Shared Folder?, SLYCK, June 30, 2004 (“When it 

67
 

comes to shared personal information, the most prolific network seems to be Gnutella.”), 

http://www.slyck.com/news.php?story=536.

54 P2P United, Member Code of Conduct (Sept. 29, 2003), 

http://wiki.morpheus.com/~p2punited/code.php. 

55 Cf. 18 U.S.C. § 1030 (2006).

56 Thomas Mennecke, What’s in Your Shared Folder?, SLYCK, June 30, 2004 

http://www.slyck.com/news.php?story=536.

57 Recent versions of Morpheus download and install in a way that makes it very difficult to repeat 

experiments with non-current 4-series or 5-series versions of Morpheus. Most filesharing programs use a

two-step installation process: A new user goes to a website and downloads a “stub” installer to their 

computer. When activated, this installer connects to the filesharing network and downloads a copy of the 

relevant filesharing program from another user. This two-step installation process makes it relatively easy

to find non-current versions of most filesharing programs. 

Since at least Morpheus 4.0, Morpheus has used a three-step installation process: A new user downloads a

stub-installer from a website; this stub installer then connects to the Gnutella network and downloads 

another “smart installer.” When run, this smart installer connects to the Morpheus web site and downloads 

the most recent version of Morpheus. This three-step installation process makes it difficult to obtain copies 

of non-current 4-series or 5-series versions of Morpheus that can be installed and operated repeatedly to

confirm how they behave. Nevertheless, while this smart-installer-based installation process frustrates the 

type of analysis used in this report, it also has benefits: For example, it would prevent users from

downloading and installing past versions of a program that had security flaws. Consequently, this report 

draws no adverse inferences about the installation process used by Morpheus. 

58 MARK N. COOPER, TIME FOR THE RECORDING INDUSTRY TO FACE THE MUSIC: THE POLITICAL, 

SOCIAL AND ECONOMIC BENEFITS OF PEER-TO-PEER COMMUNICATIONS NETWORKS 3, 4 (2005), 

http://www.consumerfed.org/pdfs/benefitsofpeertopeer.pdf. 

59 See P2P United, Member Code of Conduct (Sept. 29, 2003), http://wiki.morpheus.com

/~p2punited/code.php; see also Stopbadware.org, Software Guidelines (defining “badware” to include 

“software which is not easy to uninstall completely” and asserting that once uninstalled, “an application 

must not leave behind any functionality or design elements”), www.stopbadware.org/home/guidelines (last 

visited Sept. 18, 2006). 

60 Privacy and Piracy: The Paradox of Illegal File Sharing on Peer-to-Peer Networks and the 

Impact of Technology on the Entertainment Industry: Hearing Before the Senate Permanent Subcomm. on

Investigations of the Comm. On Gov’t Affairs, 108th Cong. 44 (Sept. 30, 2003) (testimony of Alan Morris, 

Executive Vice President of Sharman Networks, Ltd.).

61 When Private Files Become Public, SYDNEY MORNING HERALD, Aug. 6, 2004, available at

http://www.smh.com.au/articles/2004/08/05/1091557983595.html. 

62 Supra, n. 48. 

63 MusicLabs, LLC, An Important Word from BearShare about Keeping Your Private Information 

Private, http:/www.bearshare.com/data-security.htm (last visited Sept. 18, 2006). 

64 Scores of detailed, illustrated instructions are available on the Internet; most originate from one of 

three sources. Some instructions were provided by public-interest groups like EFF. See, e.g., Electronic 

68
 

Frontier Foundation, How Not to Get Sued by RIAA for File-Sharing, http://www.eff.org/IP/P2P/howtonotgetsued.php (last visited Sept. 18, 2006). Most were provided by colleges and universities like Duke 

University or the University of Chicago. See, e.g., University of Chicago Networking Services and

Information Technologies, Disabling Peer to Peer File Sharing, http://security.uchicago.edu/peer-topeer/no_fileshare.shtml (last visited Sept. 18, 2006). Others were provided by ISPs. For reasons discussed

below, most of these instructions now appear to be dated and inaccurate. 

65 ELECTRONIC FRONTIER FOUNDATION, RIAA V. THE PEOPLE: TWO YEARS LATER, 11 (2005), 

http://www.eff.org/IP/P2P/RIAAatTWO_FINAL.pdf. EFF speculates that this “leeching” will not harm 

filesharing networks because “there is no shortage of offshore uploaders for U.S. file sharers to rely on.” 

But see infra note 66. EFF also invokes the “darknet defense” of piracy: It claims that enforcing the law 

against users of popular filesharing programs will just drive them to adopt “darknet” technologies that 

hinder private law-enforcement efforts. EFF cites several such technologies, including DirectConnect, 

FreeNet, and MUTE. 

It is irresponsible to refer blithely to these three “darknet” programs as if they were just extra-hip-andsneaky substitutes for KaZaA. They differ significantly, and these differences can have life-altering

implications for their users and potentially life-ending implications for others. In truth, users of popular

filesharing programs are not likely to adopt these programs—if they understand the potential consequences. 

FreeNet contains a true forced-sharing feature: Every user of FreeNet must share files; the program itself 

decides which files a user will share and copies them onto the user’s hard drive. The developers of FreeNet 

admit that this means that you can only run FreeNet if you are willing to have your computer store and 

distribute violent child pornography or terrorists’ plans for a new 9-11-like attack on civilians: “If 

[harboring ‘child porn’ or ‘terrorism’] is not acceptable to you, you should not run a FreeNet node.” See 

FreeNet, Frequently Asked Questions, http://freenetproject.org/index.php?page=faq#offensive (last visited 

Sept. 18, 2006). This means that no reasonable person can run a FreeNet node. Nor should users assume

that they will be held blameless for facilitating pedophilia or terrorism just because the files distributed 

from their computer will be weakly encrypted: FreeNet’s distributors explain that this encryption does not

protect the privacy of the stored files, but it does provide “plausible deniability” so FreeNet users can deny 

knowing which files they were storing and distributing. Id. A similar attempt to use encryption as a 

blindfold to avoid knowledge of illegal acts not only failed, it backfired affirmatively: It was held to

provide evidence of the sort of “willful blindness” from which courts will infer criminal intent. See In re

Aimster Copyright Litigation, 334 F.3d 643, 650 (7th Cir. 2003).

DirectConnect software creates “closed,” non-public filesharing networks in which one user’s computer 

acts as a “hub,” as a network search-index server like those that once imposed billion-dollar liability upon 

Napster, Inc. These non-public networks do make private enforcement more difficult: And that is why 

participants in Direct Connect filesharing networks have been prosecuted criminally. See United States

Dept. of Justice, Attorney General Ashcroft Announces First Criminal Enforcement Action Against Peer-toPeer Copyright Piracy, (Aug. 25, 2004), http://www.usdoj.gov/criminal/cybercrime/operation_

gridlock.htm. One convicted felon has offered a moving account of the price of “free music” via Direct 

Connect. See Mickey Borchard, The tale of the sinking of an online music pirate, JOURNAL TIMES, Apr. 10, 

2006, http://www.journaltimes.com/articles/2006/04/10/opinion/iq_3987486.txt. 

MUTE is a specialized copyright-piracy tool. Its developer explains that MUTE “helps people break the 

law.” He admits this openly: “Sure many other P2P developers and companies blatantly lie about what 

their software is for, but I refuse to lie.” Howard Wen, Open Source P2P with MUTE, ONLAMP.COM, Aug. 

12, 2004, http://www.onlamp.com/pub/a/onlamp/2004/08/12/mute.html?page=1. MUTE, How File Sharing

Reveals Your Identity, at http://mute-net.sourceforge.net/howPrivacy.shtml (last visited Sept. 18, 2006). 

But MUTE helps its infringing users break the law through a forced-proxying feature: As with FreeNet, 

users who run MUTE must be willing to store and distribute files containing child pornography or terrorist 

training manuals. See Michael Ingram, Ants P2P2P: A New Approach to File-Sharing, SLYCK NEWS, Sept. 

69
 

13, 2004 (The developer of an open-source clone of MUTE explains that users should not worry about

distributing child pornography because “with this way of reasoning, people should still live in caves.”), 

http://www.slyck.com/news.php?story=567.

66 Daniel Hughes et al., Free Riding on Gnutella Revisited: The Bell Tolls?, IEEE DISTRIBUTED

SYSTEMS ONLINE, vol. 6, iss. 6, (June 2005), http://csdl2.computer.org/comp/mags/ds/2005/06/o6001.pdf. 

At first, it might seem odd that the authors of Revisited assert that their findings confirm the findings of

Free Riding on Gnutella: After all, the Gnutella network had not collapsed by 2005, even with levels of 

sharing far lower than those reported in 2000. But, as Revisited notes, the architecture of the Gnutella 

network had changed significantly between 2000 and 2005. In 2000, the search process on Gnutella was 

genuinely decentralized: All users participated as “peers” in the search process. This limited both the 

functionality and the scalability of Gnutella. By 2005, Gnutella had become more centralized: “Ultrapeers” 

indexed files shared by others and responded to search queries. These “ultrapeers” act as search-index 

servers like the “supernodes” on the FastTrack network or the search-index servers on the filesharing

system created by Napster, Inc. As a result, the 2005 version of Gnutella could function with lower levels 

of sharing than the 2000 version of Gnutella. This difference in architecture reconciles the findings of Free 

Riding and Revisited: The 2000 study could fairly conclude that a 34% sharing level put the 2000 version 

of Gnutella on the verge of collapse, and the 2004 study could conclude that a 15% sharing level put the

2005 version of Gnutella on the verge of collapse. 

Another study has also drawn interesting conclusions about the effects of enforcement on users’ propensity 

to share files. See Sudip Bhattacharjee, et al., Impact of Legal Threats on Online Music Sharing Activity: 

An Analysis of Music Industry Legal Actions, 49 J. L. & ECON. 91, 102-106 (April 2006) (concluding that 

the filing of “John Doe” lawsuits significantly reduced user’s propensity to share files). It reports that

before lawsuits were announced, the average and median number of audio files shared by studied KaZaA

users were, respectively, 343 and 227. After the filing of lawsuits, the average number of files shared

dropped to 93, and the median number of files shared plunged to 11. Id. at 102. The increasing difference 

between the average and median number of files shared indicates that almost all users radically curtailed 

their sharing while a few kept sharing very large numbers of files. Cf. id. at 106. The authors note that 

these undeterred high-volume sharers may have been located oversees. If so, then there should have been

few or no high-volume U.S. sharers to be targeted by subsequent rounds of lawsuits. 

67 Distributors deriving revenue from the production or use of their filesharing programs would have 

strong incentives to avoid such defections: “Leeching” users may contribute nothing to other users of a 

filesharing program, but they generate advertising revenues for its distributor. See, e.g., MGM Studios, 

Inc. v. Grokster, Ltd., 125 S. Ct. 2764, 2782 (2005) (“Since the extent of the software’s use determines the 

gain to its distributors, the commercial sense of their enterprise turns on high-volume use, which the record

shows is infringing.”). Professor Strahilevitz agrees with this analysis and proposes that distributors who 

deployed true forced-sharing features could be held vicariously liable. Lior Jacob Strahilevitz, Charismatic 

Code, Social Norms, and the Emergence of Cooperation on the File-Swapping Networks, 89 VA. L. REV. 

505, 522 n.68 (May 2003) (arguing that this “might make the peer-to-peer networks more plainly guilty of 

vicarious copyright infringement”). 

68 Cf. XAVIER GABAIX & DAVID LAIBSON, SHROUDED ATTRIBUTES, CONSUMER MYOPIA, AND 

INFORMATION SUPPRESSION IN COMPETITIVE MARKETS, NPER WORKING PAPER NO. 11755 (2005) 

(describing circumstances in which both producers and sophisticated users of a product or service can 

benefit when producers conceal information about the true costs of a product or service from “myopic” 

consumers), http://www.nber.org/papers/w11755. The “myopic” consumers discussed in Shrouded 

Attributes are not dupes for purposes of inducement liability. Nevertheless, its analysis appears highly

relevant to filesharing because it shows that both distributors and their advertising-revenue-generating,

sophisticated “leaching” users could benefit from the content added to the network by an avoidable feature

that tends to trick young or new users into sharing infringing files. 

70
 

69 KaZaA does not contain a coerced-sharing feature of the sort described here. Nevertheless, its

Participation Level feature did, as a practical matter, require users who wanted to download files from

others to share files that other users wanted to download. This Participation-Level feature may require 

users to share—and it may deter use of a copy-and-delete strategy for downloading—but users who want to

improve their ability to download by increasing their Participation Level must understand that the feature 

exists and how it works. Consequently, while KaZaA’s Participation Level feature might persuade users to

share infringing files intentionally, it is not a duping scheme. 

70 This report will not discuss the “mechanisms” in each program that seem to let sophisticated users 

disable sharing of their download folder. Confirming that these mechanisms actually work would require 

extended packet-level monitoring of the data being received and transmitted by the program in question. 

Such analysis exceeds the scope of this report, and it would be imprudent to recommend or suggest that 

users employ these “mechanisms” until extended analysis proves that they are effective. See, e.g., Hofstra 

University Student Computer Services, How to Disable File Sharing in KaZaA or Morpheus (2000)

(reporting that even if a user changed the “maximum simultaneous uploads” limit in Morpheus 2.0 to “0,” 

“Morpheus may still attempt to share files regardless of these changes”), 

http://www.hofstra.edu/StudentServ/CC/SCS/scs_Filesharing.cfm.

71 LimeWire retains an undisclosed, recursive-sharing share-folder feature in its installation-andsetup process. 

72 See Nathaniel Good and Aaron Krekelberg, FTC Comments on P2P Filesharing and Privacy, at 

http://www.ftc.gov/os/comments/p2pfileshare/050126nathanielgoodandaaronkrekelberg.pdf. 

73 Is Gnutella Dying?, THE WORLD ON A STRING, April 19, 2006, http://theworldstrung.com/?p=38. 

74 The Dark Side of a Bright Idea: Could Personal and National Security Risks Compromise the 

Potential of P2P File-Sharing Networks: Hearing Before the Senate Comm. on the Judiciary, 108th Cong. 

86 (June 17, 2003) (written statement of Consumers Union).

75 See, e.g., p2pecon@berkeley, Project Overview, http://p2pecon.berkeley.edu (last visited Sept. 18, 

2006); JOHN CHUANG, IN SEARCH OF HOMO SWAPPUS: EVOLUTION OF COOPERATION IN PEER-TO-PEER 

SYSTEMS (2005), http://p2pecon.berkeley.edu/ppt/swappus.pdf. 

76 Tim Wu, When Code Isn’t Law, 89 VA. L. REV. 679, 725 & fig. 3 (2003). 

77 Overexposed: The Threat to Privacy and Security on Filesharing Networks, a Hearing Before the

United States House of Representatives Comm. on Gov’t Reform, 108th Cong. 63 (May 15, 2003)

(testimony of Derrick Broes). 

78 TRUSECURE, THE PEER-TO-PEER HOLE IN YOUR NETWORK 2 (finding malicious code in 45% of

popular downloads and 60% of popular executable files); see also Overexposed: The Threat to Privacy and 

Security on Filesharing Networks, a Hearing Before the United States House of Representatives Comm. on

Gov’t Reform, 108th Cong. 37 (May 15, 2003) (statement of Dr. John Hale describing the Duload worm

that “copies itself to several provocatively named files within a media folder which it exposes to the P2P 

network”); see also David J. Stang, The Impact of a Peer-to-Peer File Sharing Program..., PestPatrol 

Research Center (Mar. 13, 2004) (“A P2P worm can masquerade as a desired music file, and be distributed 

the same way that other P2P files are shared. But the damage that it can cause is effectively without 

limit.”), http://research.pestpatrol.com/KnowledgeBase/Whitepapers/P2P_Impact.asp; WEBSENSE, THOSE 

AREN’T JUST FILES YOU’RE SWAPPING—THE DANGERS OF PEER-TO-PEER 6 (“P2P networks can be, and

are, easily exploited to distribute viruses and worms, allowing them to bypass normal security and filtering

barriers.”), http://www.websense.com/docs/WhitePapers/PeertoPeer.pdf; OSTERMAN RESEARCH, 

MANAGING IM AND P2P THREATS IN THE ENTERPRISE 6 (2004) (“Downloading content from P2P networks 

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bypasses corporate messaging security systems, leaving an enterprise network susceptible to viruses, 

worms, Trojans, buffer overflow vulnerabilities, spyware, adware and similar threats.”), 

http://www.spywareguide.com/whitepapers/osterman.pdf; Lance Ulanoff, Welcome to Spyware City, PC 

MAGAZINE, Apr. 6, 2005 (“Trojans and other garbage are always piggybacking on the files you want, and

sometimes masquerading as the files you want”); John E. Dunn, File-sharing app compromises power

station, PC ADVISOR, May 17, 2006 ( reporting that a virus downloaded from a filesharing network 

compromised the security of files that revealed a power plant’s security procedures, layout, control room

location, and the names and addresses of its security staff); id. (This article reports another incident in

which “Mitsubishi Electric leaked 40MB of data, some of which related to a nuclear power station.... 

Again, the culprit was a single PC using a P2P program that allowed a virus to sneak through conventional

data defenses.”). 

79 McGill Network and Communications Services, Introduction to P2P Security (Feb. 3, 2006) at 

http://www.mcgill.ca/ncs/products/security/p2p/. 

80 Jonathan Schmidt, When Music Becomes a Security Threat, BANKERS’ IDEANET, July 2003, 

http://www.sheshunoff.com/email/archive/0703/oper_new1.html; see also BLUECOAT, ESTABLISHING AN 

INTERNET USE POLICY TO ADDRESS PEER-TO-PEER (P2P) USE 2 (2004),

http://www.bluecoat.com/downloads/whitepapers/BCS_Controlling_P2P_survey.pdf; see also TRUSECURE, 

THE PEER-TO-PEER HOLE IN YOUR NETWORK 2 (“blocking your users from using KaZaA is almost 

impossible”); OSTERMAN RESEARCH, MANAGING IM AND P2P THREATS IN THE ENTERPRISE 1 (2004) (P2P

clients “are quite adept at circumventing existing security defenses”), 

http://www.spywareguide.com/whitepapers/osterman.pdf; Overexposed: The Threat to Privacy and 

Security on Filesharing Networks: Hearing Before the United States House of Representatives Comm. on

Gov’t Reform, 108th Cong. 29 (May 15, 2003) (written testimony of Jeffrey I. Schiller, Security Architect, 

MIT at 29) (“The authors of the peer to peer file sharing networks continue to modify and adapt their 

programs with the apparent goal, among others, of subverting attempts to control them.”); id. (“[A] major 

risk of peer to peer filesharing is that it attempts to subvert legitimate controls placed on its use.”). 

Common evasion tactics include port-hopping, tunneling and push-message requests. See, e.g.,id. at 36 

(written testimony of Dr. John Hale, Director, Center for Information Security, University of Tulsa) 

(“Another commonly used trick is for P2P clients to vary their communication ports—a technique called 

port hopping. This thwarts blocking and scanning software....”); SANDVINE, MEETING THE CHALLENGE OF

TODAY’S EVASIVE P2P TRAFFIC 9 (2004) (discussing tunneling and noting, “The P2P development

community ... has developed several tactics for hiding the true identity of packets.”), 

http://www.sandvine.com/solutions/resource_library.asp. 

81 WEBSENSE, THOSE AREN’T JUST FILES YOU’RE SWAPPING—THE DANGERS OF PEER-TO-PEER 10

(“[T]here is no business application for the use of P2P file sharing in most organizations....”), 

http://www.websense.com/docs/WhitePapers/PeertoPeer.pdf; BLUECOAT, ESTABLISHING AN INTERNET USE 

POLICY TO ADDRESS PEER-TO-PEER (P2P) USE 2 (2004) (“The business value of P2P file sharing is very

limited.... Most businesses derive no value from P2P file sharing on their networks....”),

http://www.bluecoat.com/downloads/whitepapers/BCS_Controlling_P2P_survey.pdf; id. at 4 (“P2P use 

does not generally serve a productive business function; therefore, there is no need for it to exist on the 

corporate network.”); OSTERMAN RESEARCH, MANAGING IM AND P2P THREATS IN THE ENTERPRISE 4 

(2004) (“P2P networks ... have far less—if any—legitimate use in a corporate environment....”), 

http://www.spywareguide.com/whitepapers/osterman.pdf; JIM MURPHY & DAVE ZWIEBACK, PROTECTING

THE ENTERPRISE FROM INSTANT MESSAGING AND PEER-TO-PEER THREATS 6 (2005) (“In the majority of

enterprise settings, it is almost impossible to find justification for the use of current incarnations of Internet 

peer-to-peer filesharing applications.”), 

http://www.surfcontrol.com/general/assets/whitepapers/IM_and_P2P_whitepaper.pdf. 

82 MGM Studios, Inc. v. Grokster, Ltd., 259 F. Supp. 2d 1029, 1041 (C.D. Cal. 2003), aff’d, 380 F.3d

1154 (9th Cir. Cal. 2004), rev’d, 125 S. Ct. 2764 (2005).

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83 LAWRENCE LESSIG, CODE 57 (1999) (calling this the “bovine account” of human nature). 

84 The amicus brief filed by the Berkman Center law professors in Alaujan theorizes that users of 

filesharing programs who have shared files unintentionally may not be liable even under a theory of strict

liability because sharing can occur “without the [user’s] participation” or “without [the user] acting at all.” 

Brief of Amicus Curiae Reviewing Issues of Fact and Law at 44 n.46, Capitol Records, Inc. v. Alaujan, No. 

1:03-CV-11661-NG (Dist. Mass. May 24, 2004). This is incorrect: None of the “features” discussed here 

can cause sharing absent some affirmative “participation” and “act” by the user of the program. In the

cases of redistribution and coerced-sharing features, the act is downloading. In the case of share-folder and 

search-wizard features, the act is activating the feature and accepting the results. Consequently, the

problem is not that users can share files inadvertently without acting at all. Rather, it is that users may 

share files inadvertently because filesharing programs often do a poor job of ensuring that users will 

understand the consequences of their own actions. In such cases, a contribution or other legal action by the 

user against the distributor of the program in question may provide a means to assess the relative 

culpability and contribution of their respective acts to any resulting infringement. See infra note. 87. 

85 Lior Jacob Strahilevitz, Charismatic Code, Social Norms, and the Emergence of Cooperation on

the File-Swapping Networks, 89 VA. L. REV. 505, 553 (May 2003).

86 BMG Music v. Gonzalez, 430 F.3d 888 (7th Cir. 2005). 

87 Interscope Records v. Duty, No. 05-CV-3744-PHX-FJM, 2006 U.S. Dist. LEXIS 20214 at *9 (D. 

Ariz. Apr. 14, 2006).

88 See, e.g., Secunia Advisory: SA14555 (Mar. 15, 2005), http://secunia.com/advisories/14555/; see 

also John Leyden, Limewire patches serious snooping bugs, THE REGISTER, Mar. 16, 2005, 

www.channelregister.co.uk/2005/03/16/limewire_vuln/print.html. 

89 This report focuses on programs that “operate in a manner conceptually analogous to the Napster 

system....” Metro-Goldwyn Mayer Studios, Inc. v. Grokster, Ltd., 259 F. Supp. 2d 1029, 1032 (C.D. Cal. 

2003); see also Grokster, 125 S. Ct. at 2781 (“Morpheus software functions as Napster did, except that it

could be used to distribute more kinds of files....”).

90 For a useful survey of most of the reported studies and their methodology, see Danny Hughes, 

James Walkerdine, and Kevin Lee, Monitoring Challenges and Approaches for P2P File-Sharing Systems,

INT’L CONF. ON INTERNET SURVEILLANCE AND PROTECTION, 18 (2006). 

The published studies cited in this report rely on data collected from filesharing networks from 2000

through 2004. There are also two presently unpublished analyses of data collected during 2005. 

Individually and collectively, they are very interesting.

The first analysis arose after an author of this report asked the authors of Free Riding on Gnutella

Revisited: The Bell Tolls? whether they had collected any additional trace data since May of 2004. They

graciously analyzed trace data collected in March of 2005 for another study, Is Deviant Behavior the Norm

on Peer-to-Peer File-Sharing Networks?, IEEE DISTRIBUTED SYSTEMS ONLINE, vol. 7, iss. 2, (Feb. 2006). 

Preliminary analysis of their March 2005 data showed that 93.3% of studied users shared no files. 

A second unpublished study is Shanyu Zhao, Daniel Stutzbach, Reza Rejaie, Characterizing Files in the

Modern Gnutella Network: A Measurement Study at http://www.cs.uoregon.edu/~reza/PUB/mmcn06.pdf. 

This study used a different method to collect data from the Gnutella network during June, August, and 

October of 2005. Characterizing tried to study the population of Gnutella users by using a crawler to 

identify users participating in the network and then using the browse-host feature implemented in programs 

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like LimeWire and BearShare to identify the files that each user was sharing. Characterizing reported that 

the studied users shared an average of about 350 files, and that only 13% shared no files. 

The 13% free-riding rate reported in Characterizing is interesting when compared against the 93% freeriding rate derived from the March 2005 dataset used in Deviant Behavior. The vast discrepancy in these 

results may result from some fundamental, but as yet unidentified, change in the programs themselves. 

Nevertheless, the different data-collection methods used in Deviant Behavior and Characterizing could 

explain some or even most of the differences in user’s sharing behavior. As Characterizing notes, its datacollection method would work only if a particular user 1) was connected to the network for a relatively

long time; 2) was not firewalled; and 3) had not disabled the browse-host feature. In practice, this method

worked only 18.5% of the time. 

As a result, the data-collection method used in Characterizing may tend to show – not the sharing behavior

of Gnutella users generally – but the behavior of the two disparate subgroups of users who would be likely

to be running an unfirewalled, browse-host enabled filesharing program for relatively long periods. One

subgroup might consist of highly unsophisticated users who were using browse-host-enabled filesharing 

programs without a firewall. The other subgroup might consist of sophisticated “true-believers” in

filesharing who had both the expertise and the motivation needed to configure their firewall in order to give

a filesharing program unrestricted access to the Internet. See, e.g., BearShare, Gnutella Good Citizen Tips

at http://www.bearshare.com/help/citizen.htm (last visited June 19, 2006) (“You don't need to get rid of 

your firewall completely, you just need to "drill a hole" in it for BearShare. It won't decrease your security 

because BearShare doesn't contain any security holes.”) Both groups would be very likely to be sharing 

files, and in significant numbers, though probably for very different reasons. 

In short, while it is too early to draw conclusions about the 2005 datasets, they are intriguing, and they 

suggest that more remains to be learned about the effects that program design and legal enforcement have 

upon users’ propensity to share files.

91 See supra, n.11. 

92 In effect, a filesharing program is said to create a “decentralized” filesharing network if it has been

designed to create search-index servers—and perhaps even dedicated fileservers—on computers owned by

parties other than the distributor of the filesharing program. So used, the term “decentralized” has a legal 

rather than technical meaning: Napster, Inc., could thus have converted its “centralized” filesharing 

network into a “decentralized” filesharing network just by giving the computers that housed its searchindex servers to third parties. See Edward Felten, “Centralized” Sites Not So Centralized After All, 

FREEDOM TO TINKER, Oct. 6, 2005 (“The issue is who controls those computers.”), http://www.freedomto-tinker.com/?p=906. 

93 Under early versions of the Gnutella protocol, users did participate as peers in a decentralized 

search process, but the programs discussed here now create “ultrapeers,” (search-index servers), on the 

computers of users who have high-speed Internet access. See supra note. 66. Reports also indicate that

these programs now, whenever possible, thwart the actual peer-to-peer file transfers that once occurred 

over the Napster, Inc. network: By default, these programs will redirect a user’s request to download a file 

from another “peer” user to a specialized, high-speed, terabyte-sized fileserver that exists solely to store 

and transfer files “shared” over filesharing networks. Programs use this fileserver-based architecture by 

default because “downloads ... are faster”: “[E]nd-users typically experience a net acceleration effect of 

2x—4x.” Joltid, Benefits and Recent Statistics, http://www.joltid.com/index.php/peercache/ 

benefits_and_recent_statistics (last visited March 1, 2005) (available at http://web.archive.org 

/web/20041027021141/http://www.joltid.com/index.php/peercache/ benefits _and_recent_statistics). For 

example, the owner of the FastTrack protocol and the KaZaA filesharing program warns users that 

disabling use of these fileservers and actually downloading files from peers “will most likely slow down

downloads dramatically.” Id. at http://www.joltid.com/index.php/peercache/faq/enduser (last visited March 

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1, 2005) (available at http://web.archive.org/web/20041022005537/www.joltid.com/ 

index.php/peercache/faq/enduser). This report does not reconcile this reported preference for faster, 

fileserver-based file transfers with representations about the alleged advantages of peer-to-peer file

transfers made to the Supreme Court and the Federal Trade Commission. See, e.g., MGM Studios, Inc. v.

Grokster, Ltd., 125 S. Ct. 2764, 2770 (2005) (“[peer-to-peer] file ... retrievals may be faster than on other 

types of networks”); Brief for Respondents at 3, MGM Studios Inc. v. Grokster, Ltd., No. 04-480 (March 1, 

2005) (“if material sought by a user already resides on other users’ computers that can be accessed over

already-in-place communication lines, then it is a wasteful redundancy also to store the material on a group

of central servers”). 

75