Document ID: s3://data.kl3m.ai/documents/govinfo/USCOURTS/USCOURTS-ca13-09-01372/USCOURTS-ca13-09-01372-3/pdf.json

Parties Involved:
Akamai Technologies, Inc.
Appellant
Limelight Networks, Inc.
Cross-Appellant
Massachusetts Institute of Technology
Appellant

Document Text:

United States Court of Appeals 

for the Federal Circuit ______________________

AKAMAI TECHNOLOGIES, INC., 

THE MASSACHUSETTS INSTITUTE OF 

TECHNOLOGY,

Plaintiffs-Appellants

v.

LIMELIGHT NETWORKS, INC.,

Defendant-Cross-Appellant

______________________

2009-1372, 2009-1380, 2009-1416, 2009-1417

______________________

Appeals from the United States District Court for the 

District of Massachusetts in Nos. 06-CV-11585, 06-CV11109, Judge Rya W. Zobel.

______________________

Decided: May 13, 2015

______________________

SETH P. WAXMAN, Wilmer Cutler Pickering Hale and 

Dorr LLP, Washington, DC, argued for plaintiffsappellants. Also represented by THOMAS SAUNDERS,

THOMAS GREGORY SPRANKLING; MARK CHRISTOPHER

FLEMING, ERIC FLETCHER, LAUREN B. FLETCHER, BROOK 

HOPKINS, Boston, MA; DAVID H. JUDSON, Law Offices of 

David H. Judson, Dallas, TX; DONALD ROBERT DUNNER,

KARA F. STOLL, ELIZABETH D. FERRILL, Finnegan, Henderson, Farabow, Garrett & Dunner, LLP, Washington, DC;

JENNIFER S. SWAN, Palo Alto, CA; ROBERT S. FRANK, JR.,

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2 AKAMAI TECHNOLOGIES, INC. v. LIMELIGHT NETWORKS, INC.

G. MARK EDGARTON, CARLOS PEREZ-ALBUERNE, Choate, 

Hall & Stewart, LLP, Boston, MA. 

AARON M. PANNER, Kellogg, Huber, Hansen, Todd, 

Evans & Figel, P.L.L.C., Washington, DC, argued for 

defendant-cross appellant. Also represented by JOHN 

CHRISTOPHER ROZENDAAL, MICHAEL E. JOFFRE; 

ALEXANDER FRASER MACKINNON, Kirkland & Ellis LLP, 

Los Angeles, CA; YOUNG JIN PARK, New York, NY; DION 

D. MESSER, Limelight Networks, Inc., Tempe, AZ. 

JERRY ROBIN SELINGER, Patterson & Sheridan LLP, 

Dallas, TX, for amici curiae Altera Corporation, HTC 

America, Inc., HTC Corporation, Weatherford International, Inc. Also represented by B. TODD PATTERSON, 

Houston, TX; GERO MCCLELLAN, Greensboro, NC.

WILLIAM G. BARBER, Pirkey Barber LLP, Austin, TX, 

for amicus curiae American Intellectual Property Law 

Association.

TIMOTHY TETER, Cooley LLP, Palo Alto, CA, for amicus curiae Apple Inc. Also represented by BENJAMIN G.

DAMSTEDT, IAIN R. CUNNINGHAM, LORI R. MASON; PATRICK 

J. MURPHY, Apple Computer Inc., Cupertino, CA.

MEREDITH MARTIN ADDY, Katten Muchin Rosenman 

LLP, Chicago, IL, for amici curiae Aristocrat Technologies 

Australia PTY Limited, Aristocrat Technologies, Inc. Also 

represented by ANTHONY R. DE ALCUAZ, McDermott, Will 

& Emery LLP, Menlo Park, CA.

JOHN W. RYAN, Thompson Hine LLP, Washington, 

DC, for amicus curiae Biotechnology Industry Organization. Also represented by HANSJORG SAUER, Biotechnology 

Industry Organization, Washington, DC; THOMAS M.

HAAS, Sullivan & Worcester, Washington, DC.

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AKAMAI TECHNOLOGIES, INC. v. LIMELIGHT NETWORKS, INC. 3

JEFFREY E. FRANCIS, Pierce Atwood LLP, Boston, MA, 

for amicus curiae Boston Patent Law Association. 

GREGORY PAUL STONE, Munger, Tolles & Olson LLP, 

Los Angeles, CA, for amicus curiae CTIA The Wireless 

Association. Also represented by HEATHER E. TAKAHASHI,

ANDREW W. SONG.

RAYMOND PARDO NIRO, I, Niro, Haller & Niro, Chicago, IL, for amici curiae Cascades Ventures, Inc., VNS 

Corporation. Also represented by JOHN C. JANKA.

EDWARD R. REINES, Weil, Gotshal & Manges LLP, 

Redwood Shores, CA, for amici curiae Cisco Systems, Inc., 

Dell Inc., Google Inc., Hewlett-Packard Company, Intel 

Corporation, Intuit Inc., Micron Technology, Inc., NetApp, 

Inc., Ringcentral, Inc., SAP America, Inc., Symantec 

Corporation, Yahoo! Inc., Zynga Inc., Ebay, Inc. Also 

represented by NATHAN A. GREENBLATT.

STEVEN C. SEREBOFF, SoCal IP Law Group LLP, 

Westlake Village, CA, for amicus curiae Conejo Valley 

Bar Association. Also represented by MEENAKSHI KALA 

SARVAIYA, MARK ANDREW GOLDSTEIN.

JULIE P. SAMUELS, Electronic Frontier Foundation,

San Francisco, CA, for amicus curiae Electronic Frontier 

Foundation. Also represented by MICHAEL BARCLAY.

MATTHEW D. MCGILL, Gibson, Dunn & Crutcher LLP, 

for amici curiae Facebook, Inc., LinkedIn Corporation, 

Also represented by WILLIAM G. JENKS, Jenks IP Law, 

Washington, DC.

JOHN STEVEN GARDNER, Kilpatrick Townsend & 

Stockton LLP, Winston-Salem, NC, for amicus curiae The 

Financial Services Roundtable. Also represented by 

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4 AKAMAI TECHNOLOGIES, INC. v. LIMELIGHT NETWORKS, INC.

ALTON LUTHER ABSHER; GIA L. CINCONE, San Francisco, 

CA.

PETER J. BRANN, Brann & Isaacson, Lewiston, ME, for 

amicus curiae Internet Retailers. Also represented by 

STACY O. STITHAM, DAVID SWETNAM-BURLAND.

GARRETH A. SAROSI, Winstead Attorneys, Dallas, TX, 

for amicus curiae MetroPCS Wireless, Inc. Also represented by MARK ATKERSON STACHIW, Metro PCS Communications Inc., Richardson, TX.

BENJAMIN JACKSON, Myriad Genetics, Salt Lake City, 

UT, for amicus curiae Myriad Genetics, Inc. Also represented by JAY Z. ZHANG.

CHARLES A. WEISS, Kenyon & Kenyon LLP, New York, 

NY, for amicus curiae New York Intellectual Property 

Law Association. Also represented by THERESA M. GILLIS, 

Mayer Brown, LLP, New York, NY.

ROBERT P. TAYLOR, Arnold & Porter, LLP, San Francisco, CA, for amicus curiae Pharmaceutical Research and 

Manufacturers of America. Also represented by MONTY 

AGARWAL; LISA A. ADELSON, DAVID R. MARSH, Washington, DC; DAVID EVAN KORN, Pharmaceutical Research and 

Manufacturers Association of America, Washington, DC.

VICKI GEE NORTON, Duane Morris LLP, San Diego, 

CA, for amicus curiae The San Diego Intellectual Property 

Law Association.

ERIC LAURENCE ABBOTT, Abbott Law Chartered, Las 

Vegas, NV, for amicus curiae Shuffle Master, Inc.

CALVIN L. LITSEY, Faegre Baker Daniels LLP, Minneapolis, MN, for amicus curiae Thomson Reuters CorporaCase: 09-1372 Document: 316-2 Page: 4 Filed: 05/13/2015
AKAMAI TECHNOLOGIES, INC. v. LIMELIGHT NETWORKS, INC. 5

tion. Also represented by TIMOTHY M. SULLIVAN, AARON D.

VAN OORT, CHRISTOPHER J. BURRELL.

MICHAEL K. KIRSCHNER, Hillis, Clark, Martin & Peterson P.S., Seattle, WA, for amicus curiae Washingon 

State Patent Law Association. Also represented by 

ALEXANDER M. WU.

CHARLES R. MACEDO, Amster Rothstein & Ebenstein 

LLP, New York, NY, for amici curiae Double Rock Corporation, Island Intellectual Property, LLC, Broadband ITV, 

Inc. Also represented by JESSICA A. CAPASSO. 

______________________

Before PROST, Chief Judge, LINN, and MOORE,

∗ Circuit 

Judges.

Opinion for the court filed by Circuit Judge LINN.

Dissenting opinion filed by Circuit Judge MOORE.

LINN, Circuit Judge.

This appeal returns to us following remand from the 

United States Supreme Court. See Limelight Networks, 

Inc. v. Akamai Techs., Inc., 134 S. Ct. 2111 (2014). Because our prior decisions in BMC Resources, Inc. v. Paymentech, L.P., 498 F.3d 1373 (Fed. Cir. 2007), and 

Muniauction, Inc. v. Thomson Corp., 532 F.3d 1318 (Fed. 

Cir. 2008), directly apply to the facts of this case and 

because the statutory framework of 35 U.S.C. § 271 does 

not admit to the sweeping notions of common-law tort 

liability argued in this case, we again conclude that 

∗ Pursuant to Fed. Cir. Internal Operating Procedure 15 ¶ 2(b)(ii) (Nov. 14, 2008), Circuit Judge Moore 

was designated to replace Randall R. Rader, now retired, 

on this panel.

 

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6 AKAMAI TECHNOLOGIES, INC. v. LIMELIGHT NETWORKS, INC.

because Limelight Networks, Inc. (“Limelight”) did not 

perform all of the steps of the asserted method claims of 

U.S. Patent No. 6,108,703 (the “’703 patent”) and because 

the record contains no basis on which to impose liability 

on Limelight for the actions of its customers who carried 

out the other steps, Limelight has not directly infringed 

the ’703 patent under § 271(a). Accordingly, we affirm the 

district court’s finding of noninfringement and do not 

reach Limelight’s cross-appeal regarding damages. We 

also confirm our previously reinstated affirmance of the 

district court’s judgment of noninfringement of U.S. 

Patents No. 6,553,413 (the “’413 patent”) and No. 

7,103,645 (the “’645 patent”). See Akamai, 629 F.3d 1311 

(Fed. Cir. 2010), which was vacated, 419 F. App’x 989 

(Fed. Cir. 2011) (en banc), and then partially reinstated. 

Order No. 2009-1372 (Fed. Cir. Sept. 27, 2012) (en banc).

I. BACKGROUND

A detailed description of the history of proceedings, 

the technology and the claims at issue in this case is set 

forth in the prior reported opinions of this court and the 

Supreme Court and will not be repeated except to the 

extent germane hereto. See Limelight, 134 S. Ct. 2111; 

Akamai, 692 F.3d 1301 (Fed. Cir. 2012) (en banc); Akamai, 629 F.3d 1311.

II. DIVIDED INFRINGEMENT UNDER § 271(a)

In the court’s view, and for the reasons set forth in 

more detail, infra, direct infringement liability of a method claim under 35 U.S.C. § 271(a) exists when all of the 

steps of the claim are performed by or attributed to a 

single entity—as would be the case, for example, in a 

principal-agent relationship, in a contractual arrangeCase: 09-1372 Document: 316-2 Page: 6 Filed: 05/13/2015
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ment, or in a joint enterprise.1 Because this case involves 

neither agency nor contract nor joint enterprise, we find 

that Limelight is not liable for direct infringement.

Direct infringement under § 271(a) requires a party to 

perform or use each and every step or element of a 

claimed method. Warner-Jenkinson Co. v. Hilton Davis

Chem. Co., 520 U.S. 17, 29 (1997). For method patent 

claims, direct infringement only occurs when a single 

party or a joint enterprise performs all of the steps of the 

process. See Joy Techs., Inc. v. Flakt, Inc., 6 F.3d 770, 775 

(Fed. Cir. 1993) (“A method claim is directly infringed 

only by one practicing the patented method.” (emphasis 

omitted)); Fromson v. Advance Offset Plate, Inc., 720 F.2d 

1565, 1567–68 (Fed. Cir. 1983) (“Because the [method] 

claims include the application of a diazo coating or other 

light sensitive layer and because Advance’s customers, 

not Advance, applied the diazo coating, Advance cannot 

be liable for direct infringement with respect to those 

plates.”). This holding derives from the statute itself, 

which states “whoever without authority makes, uses, 

offers to sell, or sells any patented invention, within the 

United States or imports into the United States any 

patented invention during the term of the patent therefor, 

infringes the patent.” § 271(a). Encouraging or instructing others to perform an act is not the same as performing 

the act oneself and does not result in direct infringement. 

BMC, 498 F.3d at 1378–79. This is evidenced by the fact 

that § 271 has separate subsections addressing induced 

and contributory infringement. When a party participates in or encourages infringement but does not directly 

infringe a patent, the normal recourse under the law is for 

1 Because this case does not implicate joint enterprise liability, this case is not the appropriate vehicle to 

adopt joint enterprise liability.

 

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the court to apply the standards for liability under indirect infringement. Id. However, indirect infringement 

requires, as a predicate, a finding that some party is 

directly liable for the entire act of direct infringement. 

Limelight, 134 S. Ct. at 2115. In circumstances in which 

one party, acting as “mastermind” exercises sufficient 

“direction or control” over the actions of another, such 

that those actions may be attributed to the mastermind, 

the combined performance of the steps of a method claim 

will directly infringe under § 271(a). BMC, 498 F.3d at 

1382. “Under BMC Resources, the control or direction 

standard is satisfied in situations where the law would 

traditionally hold the accused direct infringer vicariously 

liable for the acts committed by another party that are 

required to complete performance of a claimed method.” 

Muniauction, 532 F.3d at 1330. This may occur in a 

principal-agent relationship, a contractual relationship or 

in circumstances in which parties work together in a joint 

enterprise functioning as a form of mutual agency.

Akamai asserts that the Supreme Court’s Limelight

decision “strongly implies that a change in direction on 

§ 271(a) is warranted.” Br. for Akamai at 3, Akamai, No. 

2009-1372 (Fed. Cir. Aug. 18, 2014) (“Akamai’s Letter 

Br.”). It claims that in lieu of overruling Muniauction, 

this panel can decline to extend it to the facts of this case. 

Id. According to Akamai, an accused infringer “directs or 

controls” a third party if the accused infringer goes beyond loosely providing instructions and specifically tells a 

third party the step or steps to perform. Id. at 9. In its en 

banc briefing, Akamai cites joint tortfeasor principles as 

support. See, e.g., Principal Br. for Pls.-Appellants at 21, 

Akamai, 692 F.3d 1301 (available at 2011 WL 2822716)

(citing Restatement (Second) of Agency § 212, cmt. a 

(discussing the tort principle that “one causing and intending an act or result is as responsible as if he had 

personally performed the act or produced the result”)); id.

at 22 (quoting Restatement (Second) of Torts § 877(a) 

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(subjecting a party to liability for “order[ing]” conduct)). 

Limelight responds that Akamai’s expansive attribution 

theory “would render both Section 271(b) and Section 

271(c) meaningless.” Br. of Def.-Cross-Appellant Limelight Networks, Inc. on Rehearing En Banc at 41, Akamai, 

692 F.3d 1301 (available at 2011 WL 3796785) (quoting 

Mark A. Lemley et al., Divided Infringement Claims, 6 

Sedona Conf. J. 117, 119–20 (2005) (“Lemley”)).

We begin by considering whether § 271(a) incorporates joint tortfeasor liability, as Akamai and the dissent 

advocate. Unquestionably, it does not. As codified by 

Congress, § 271(a) includes only the principles of vicarious 

liability, as embodied in the single entity rule. Presented 

with numerous conflicting theories of joint liability that 

existed in the common law prior to 1952, Congress enacted specific rules for inducement and contributory liability 

in § 271(b) and (c), respectively. While the dissent believes this leaves a “gaping hole,” Dissent at 1, it is not 

our position to legislate or contravene Congress’ choice—

right or wrong—by importing other theories of joint 

liability into § 271(a).

The alternative—stretching § 271(a) to include joint 

tortfeasor liability—is flawed. To make joint tortfeasor 

liability consistent with the well-established fact that 

direct infringement liability under § 271(a) is strict liability, Akamai and the dissent must abandon several core 

tenets of joint tortfeasor law. This position also leads to

untenable results. For example, the dissent advocates 

holding a customer jointly and severally liable for patent 

infringement based on its performance of a single step of 

a claimed method, even when it has no knowledge of the 

patent.

In the analysis that follows we address, in turn, three 

subjects: the statutory scheme of § 271, the divided infringement case law, and the errors in importing joint 

tortfeasor liability into § 271(a).

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A. The Statutory Scheme of § 271

Patent infringement is not a creation of common law. 

It is a tort defined by statute. See Crown Die & Tool Co. 

v. Nye Tool & Mach. Works, 261 U.S. 24, 40 (1923) (“The 

monopoly [granted to the patentee] did not exist at common law, and the rights, therefore, which may be exercised under it cannot be regulated by the rules of the 

common law.” (quoting Gayler v. Wilder, 51 U.S. (10 

How.) 477, 494 (1850))); 3D Sys., Inc. v. Aarotech Labs., 

Inc., 160 F.3d 1373, 1379 (Fed. Cir. 1998) (“Defining the 

contours of the tort of infringement, which exists solely by 

virtue of federal statute, entails the construction of the 

federal statute and not a state’s common or statutory 

law.” (citing N. Am. Philips Corp. v. Am. Vending Sales, 

Inc., 35 F.3d 1576, 1579 (Fed. Cir. 1994)).

35 U.S.C. § 271(a) provides that:

Except as otherwise provided in this title, whoever without authority makes, uses, offers to sell, or 

sells any patented invention, within the United 

States or imports into the United States any patented invention during the term of the patent 

therefor, infringes the patent.

Section 271(a) defines infringement. H.R. Rep. No. 82-

1923, at 9 (1952) (“Section 271, paragraph (a), is a declaration of what constitutes infringement.” (emphasis added)). Subsections (b) and (c), in turn, codify the doctrines 

of inducement and contributory infringement respectively.

The Supreme Court has observed that “the 1952 Act 

did include significant substantive changes, and . . . § 271 

was one of them.” Dawson Chem. Co. v. Rohm & Haas 

Co., 448 U.S. 176, 204 (1980). In the 1952 Patent Act, 

Congress removed joint-actor patent infringement liability from the discretion of the courts, defining “infringement” in § 271(a) and expressly outlining in § 271(b) and 

(c) the only situations in which a party could be liable for 

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something less than an infringement. This was purposeful. At the time, the courts applied a myriad of approaches to multi-actor infringement: some liberally allowed for 

multi-actor liability, see, e.g., Peerless Equip. Co. v. W.H. 

Miner, Inc., 93 F.2d 98, 105 (7th Cir. 1937); Solva Waterproof Glue Co. v. Perkins Glue Co., 251 F. 64, 73–74 (7th 

Cir. 1918), while others nearly never permitted multiactor liability, see, e.g., Mercoid Corp. v. Mid-Continent 

Inv. Co., 320 U.S. 661, 669 (1944) (“[w]hat residuum [of 

contributory infringement] may be left we need not stop to 

consider”); Mercoid Corp. v. Minneapolis-Honeywell 

Regulator Co., 320 U.S. 680, 684 (1944). In enacting 

§ 271(b) and (c), Congress cleared away the morass of 

multi-actor infringement theories that were the unpredictable creature of common law in favor of two infringement theories that it defined by statute. See Contributory 

Infringement in Patents—Definition of Invention: Hearings on H.R. 5988, 4061, and 5248 Before the Subcomm. 

on Patents, Trademarks, and Copyrights of the H. Comm. 

on the Judiciary, 80th Cong. 12 (1948) (statement of Giles 

S. Rich on behalf of the New York Patent Law Ass’n)

(“contributory infringement is a specific application to 

patent law of the law of joint tort feasor”); Hearing on 

H.R. 3866 Before Subcomm. No. 4 of the H. Comm. on the 

Judiciary, 81st Cong. 2 (1949) (statement of Giles S. Rich 

on behalf of the New York Patent Law Ass’n) (“Time out 

of mind, under the old common law, there has been a 

doctrine of joint tort feasors to the effect that people who 

jointly commit a tort are jointly and severally liable. This 

contributory infringement is nothing but the application 

of that doctrine to patent law.”); id. at 3, 6–7; Giles S. 

Rich, Infringement Under Section 271 of the Patent Act of 

1952, 35 J. Pat. Off. Soc’y 476, 480 (1953) (“Contributory 

infringement is an expression of the old common law 

doctrine of joint tort feasors.” (emphases in original)).

Indeed, in this way, Congress carefully crafted subsections (b) and (c) to expressly define the only ways in 

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which individuals not completing an infringing act under 

§ 271(a) could nevertheless be liable. See, e.g., Dawson, 

448 U.S. at 187–214 (discussing at length the state of 

contributory infringement prior to the 1952 Patent Act 

and the legislative history of the 1952 Act). Therefore, to 

the extent that tort law’s contributory liability principles 

are applicable at all, § 271(b) and (c) embody the application of contributory liability principles to patent law. See

Cent. Bank of Denver, N.A. v. First Interstate Bank of 

Denver, N.A., 511 U.S. 164, 184 (1994) (“The fact that 

Congress chose to impose some forms of secondary liability, but not others, indicates a deliberate congressional 

choice with which the courts should not interfere.”). We 

must respect Congress’ deliberate choice to enact only 

certain forms of contributory liability in § 271(b) and (c).2

2 Akamai and the dissent argue that the word 

“whoever” in § 271(a) (“whoever . . . uses . . . any patented 

invention”) undermines the single entity rule because it is 

plural. See 1 U.S.C. § 1 (“In determining the meaning of 

any Act of Congress, unless the context indicates otherwise—words importing the singular include and apply to 

several persons, parties, or things . . . .” (emphasis added)). The court agrees that “whoever” is plural, but Akamai and the dissent’s argument fails for two reasons.

First, the statute simply states the obvious: more than 

one entity can be independently liable for direct patent 

infringement if each entity practices every element of the 

claim. Second, the statutory context, with § 271(b) and (c) 

extending liability in limited circumstances to actors who 

do not independently infringe, establishes that § 271(a) 

excludes joint liability. 

The dissent’s interpretation of “whoever” as “any person or persons” is also too sweeping for its purposes. The 

 

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Furthermore, Akamai’s broad theory of attribution—

in which a defendant would be liable for “causing and 

intending an act or result,” Akamai’s Letter Br. at 4

(citations omitted)—would render § 271(b) redundant. 

Subsection (b) states: “Whoever actively induces infringement of a patent shall be liable as an infringer.” 

The Supreme Court in Global-Tech, quoting Webster’s, 

explained that to induce “means to lead on; to influence; 

to prevail on; to move by persuasion or influence.” GlobalTech Appliances, Inc. v. SEB S.A., 131 S. Ct. 2060, 2065

(2011) (quoting Webster’s New International Dictionary 

1269 (2d ed. 1945)) (internal citations and brackets omitted). Webster’s contains several, somewhat overlapping, 

definitions for “induce,” one of which is “cause.” Webster’s 

at 1269; accord Dansereau v. Ulmer, 903 P.2d 555, 564 

(Alaska 1995); United States v. McQueen, 670 F.3d 1168, 

1170 (11th Cir. 2012). And even the definitions expressly 

quoted in Global-Tech—namely: to lead on; to influence; 

to prevail on; to move by persuasion or influence—are all 

ways to “cause.” The Supreme Court in Global-Tech

further explained that the adverb “actively” means that 

“the inducement must involve the taking of affirmative 

steps to bring about the desired result.” 131 S. Ct. at 

2065 (citing Webster’s at 27). This “obviously [requires] 

plain meaning of § 271(a), as the dissent would have it, 

contains no requirement that the parties “act in concert

pursuant to a common plan or design,” Dissent at 21, and

the dissent introduces it with no statutory basis. The 

dissent’s analogy to joint inventors, see id. at 10, 15, 16,

only underscores this problem. That joint inventors must 

have some connection derives from the word “jointly”

found in § 116—see, e.g., Bard Peripheral Vascular, Inc. v. 

W.L. Gore & Assocs., Inc., 776 F.3d 837, 846 (Fed. Cir. 

2015) (citing cases)—not from the word “[w]hoever.”

 

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know[ing] the action that [the inducer] wishes to bring 

about.” Id. Thus, a defendant actively induces patent 

infringement under § 271(b) if she causes infringement 

while intending the act or result to occur (along with 

certain other requirements). See Black’s Law Dictionary 

1321 (8th ed. 1999) (defining “active inducement” as “[t]he 

act of intentionally causing a third party to infringe a 

valid patent”).

But if, as Akamai contends, there is liability under 

§ 271(a) for “one causing and intending an act or result,” 

there is no need for a separate tort for induced infringement. This is crystallized by the language of the Restatement (Second) of Torts § 877(a)—cited by Akamai—

which subjects a defendant to liability for tortious conduct 

of another if the defendant “orders or induces the conduct” 

(emphasis added).

For essentially the same reasons, Akamai’s broad 

reading of § 271(a) would make § 271(c) redundant as 

well. Subsection (c), as originally enacted, stated:

(c) Whoever sells a component of a patented machine, manufacture, combination or composition, 

or a material or apparatus for use in practicing a 

patented process, constituting a material part of 

the invention, knowing the same to be especially 

made or especially adapted for use in an infringement of such patent, and not a staple article 

or commodity of commerce suitable for substantial 

noninfringing use, shall be liable as a contributory 

infringer.

As with § 271(b), liability for § 271(c) requires knowledge 

or willful blindness of the patent, Global-Tech, 131 S. Ct. 

at 2068, and requires direct infringement. Aro Mfg. Co. v. 

Convertible Top Replacement Co. (Aro II), 377 U.S. 476, 

484 (1964). Thus, § 271(c) also entails causing customers 

to act as they did and intending the acts and/or results. 

There is no principled reason why Akamai’s attribution 

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theory should not apply to combination patents. But it is 

well settled that the sale of an unpatented component will 

at most raise a question of infringement under subsection 

(c), not subsection (a). See 35 U.S.C. § 271(c); Aro Mfg. 

Co. v. Convertible Top Replacement Co. (Aro I), 365 U.S. 

336, 339–40 (1961) (because “the fabric is no more than 

an unpatented element of the combination which was 

claimed as the invention[,] [i]t follows that petitioners’ 

manufacture and sale of the fabric is not a direct infringement under 35 U.S.C. § 271(a)”).

While Akamai at various points uses slightly different 

phrasing for when one party’s actions should be attributed to another, all of its proposed tests suffer the same 

failing: they make § 271(b) and (c) redundant. Akamai’s 

proposed interpretation thus contravenes the rule that 

“we construe statutes, where possible, so as to avoid 

rendering superfluous any parts thereof.” Astoria Fed. 

Sav. & Loan Ass’n v. Solimino, 501 U.S. 104, 111 (1991).

The dissent is faced with the same problem. To manufacture a single case in which its expansive interpretation of § 271(a) would not render § 271(b) and (c) 

superfluous, the dissent imposes a requirement that each 

joint patent infringer must perform at least one step of 

the method, see Dissent at 14. However, this single step 

requirement necessitates a new and untested definition of 

the word “uses.” It also conflicts with the common law of 

torts—the authority cited by the dissent for its broad 

interpretation of § 271(a). The common law of torts would 

hold liable an entity that, with sufficient intent, aided 

another in committing a tort, even if that entity did not 

commit any element of the tort itself.

B. Divided Infringement Case Law

Under the language of § 271(a), this court’s “divided 

infringement” case law is rooted in traditional principles 

of vicarious liability. Under the principles of vicarious 

liability, direct infringement does not occur unless all 

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16 AKAMAI TECHNOLOGIES, INC. v. LIMELIGHT NETWORKS, INC.

steps of a method claim are performed by or attributable 

to a single entity. This is the single entity rule. BMC 

confirmed that where the actions of one party can be 

legally imputed to another, such that a single entity can 

be said to have performed each and every element of the 

claim, that single entity is liable as a direct infringer. 498 

F.3d at 1380–81. Before BMC, the judiciary and the 

patent law community recognized that multiple actors 

could together infringe a patent only if one controlled the 

other(s). See Mobil Oil Corp. v. Filtrol Corp., 501 F.2d 

282, 291–92 (9th Cir. 1974) (“Mobil contends that Filtrol 

and Texaco split between them the performance of the 

four steps of the claim . . . . We question whether a method claim can be infringed when two separate entities 

perform different operations and neither has control of the 

other’s activities. No case in point has been cited.” (emphasis added)); BMC Res., Inc. v. Paymentech, L.P., No. 

3:03-cv-1927, 2006 WL 1450480, at *4 (N.D. Tex. May 24, 

2006); Lemley, 6 Sedona Conf. J. at 118 (“[C]ourts have 

imposed liability for direct infringement where another 

person acts as an agent of the alleged infringer.” (emphasis added)).

Applying traditional principles of vicarious liability to 

direct infringement under § 271(a) protects patentees 

from a situation where a party attempts to “avoid infringement . . . simply by contracting out steps of a patented process to another entity . . . . It would be unfair 

indeed for the mastermind in such situations to escape 

liability.” BMC, 498 F.3d at 1381. In addition, in patent 

law, unlike in other areas of tort law—where the victim 

has no ability to define the injurious conduct upfront—the 

patentee specifically defines the boundaries of his or her 

exclusive rights in the claims appended to the patent and 

provides notice thereby to the public so that it can avoid 

infringement. As this court correctly recognized in BMC, 

“[t]he concerns over a party avoiding infringement by 

arms-length cooperation can usually be offset by proper 

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claim drafting. A patentee can usually structure a claim 

to capture infringement by a single party.” 498 F.3d at 

1381. Further, many amici have pointed out that the 

claim drafter is the least cost avoider of the problem of 

unenforceable patents due to joint infringement. It would 

thus be unwise to overrule decades of precedent in an 

attempt to enforce poorly-drafted patents.

The dissent asserts that a handful of pre-1952 cases

conflict with the single entity rule. But all of these cases 

do not involve method claims, see York & Md. Line R.R.

Co. v. Winans, 58 U.S. (17 How.) 30 (1854); ThomsonHouston Elec. Co. v. Ohio Brass Co., 80 F. 712 (6th Cir. 

1897); Wallace v. Holmes, 29 F. Cas. 74, 80 (C.C.D. Conn. 

1871); Jackson v. Nagle, 47 F. 703, 703 (C.C.N.D. Cal. 

1891); N.J. Patent Co. v. Schaeffer, 159 F. 171, 173 

(C.C.E.D. Pa. 1908)3), and/or concern contributory (as 

opposed to direct) infringement. See Peerless, 93 F.2d at

105; Solva, 251 F. at 73; Thomson-Houston, 80 F. at 721; 

Wallace, 29 F. Cas. 74.4 Cases discussing apparatus (as 

opposed to method) claims are not helpful because whoever combines the last element of an apparatus necessarily, 

3 Jackson related to a claim for infringement of 

claims 1, 4, and 5 of U.S. Patent No. 263,412 (the “’412 

patent”), claims 1 and 2 of U.S. Patent No. 269,863 (the 

“’863 patent”), and claims 2 and 3 of U.S. Patent No. 

302,338 (the “’338 patent”). 47 F. at 703. Schaeffer

related to a claim for infringement of U.S. Patent No. 

782,375 (the “’375 patent”). 159 F. at 172. None of these 

are method claims. See ’412, ’863, ’338 and ’375 patents.

4 Though Wallace does not explicitly use the term, 

it is a recognized example of contributory infringement. 

See Dawson, 448 U.S. at 187–88; Aro II, 377 U.S. at 500; 

Henry v. A.B. Dick Co., 224 U.S. 1, 34 (1912) (all describing Wallace as an example of contributory infringement).

 

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individually, “makes” the invention. Thus, in the case of 

an apparatus claim, there is always a single entity directly infringing the patent. By contrast, because “a process 

is nothing more than the sequence of actions of which it is 

comprised, the use of a process necessarily involves doing 

or performing each of the steps recited.” NTP, Inc. v. 

Research in Motion, Ltd., 418 F.3d 1282, 1318 (Fed. Cir. 

2005). As such, only method claims can raise an issue of 

divided infringement. 

The contributory infringement cases are, by their 

terms, not discussing direct infringement. The dissent 

acknowledges this, see Dissent at 20 (“some of the[se] pre1952 principles and cases . . . are more akin to what we 

today consider to be indirect infringement than direct 

infringement under § 271(a)”), but suggests that the 1952 

Act changed the contours of direct infringement, categorizing certain behaviors that formerly were described as 

contributory infringement as direct infringement. This is 

wrong. The enactment of § 271(a) “left intact the entire 

body of case law on direct infringement.” WarnerJenkinson, 520 U.S. at 26–27 (quoting Aro I, 365 U.S. at 

342). Today, just as in 1952, where a single entity does 

not perform each and every claim limitation, that entity 

may not be characterized or held liable as a direct infringer. See Aro I, 365 U.S. at 340; Fromson, 720 F.2d at

1567–68. Contributory actions—such as the performance 

of some, but not all, steps of a method claim—do not meet 

the all elements test, and thus must be analyzed exclusively under the rules of indirect infringement. BMC, 498 

F.3d at 1381 (“[E]xpanding the rules governing direct 

infringement to reach independent conduct of multiple 

actors would subvert the statutory scheme for indirect 

infringement.”). Therefore, the principles of vicarious 

liability govern § 271(a).

Turning to the scope of vicarious liability, the vicarious liability test includes, for example, principal-agent 

relationships, contractual arrangements, and joint enterCase: 09-1372 Document: 316-2 Page: 18 Filed: 05/13/2015
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prises. In a principal-agent relationship, the actions of 

the agent are attributed to the principal. Similarly, when 

a contract mandates the performance of all steps of a 

claimed method, each party to the contract is responsible 

for the method steps for which it bargained. However, 

this type of contractual arrangement will typically not be 

present in an arms-length seller-customer relationship.

Finally, in a joint enterprise, the acts of each participant are, by definition, imputed to every member.

All members of a joint venture may be jointly and 

severally liable to third persons for wrongful acts 

committed in furtherance of the joint enterprise or 

venture. Thus, the negligence of one participant 

in the enterprise or venture, while acting within 

the scope of agency created by the enterprise, may 

be imputed to another participant so as to render 

the latter liable for the injuries sustained by third 

persons as a result of the negligence.

48A C.J.S. Joint Ventures § 62 (footnotes omitted); see 

also Restatement (Second) of Torts § 491 (1965) (“Any one 

of several persons engaged in a joint enterprise, such as to 

make each member of the group responsible for physical 

harm to other persons caused by the negligence of any 

member, is barred from recovery against such other 

persons by the negligence of any member of the group.”). 

A joint enterprise exists for the purposes of imposing 

vicarious liability when there is: 

(1) an agreement, express or implied, among the 

members of the group; (2) a common purpose to be 

carried out by the group; (3) a community of pecuniary interest in that purpose, among the members; and (4) an equal right to a voice in the 

direction of the enterprise, which gives an equal 

right of control.

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20 AKAMAI TECHNOLOGIES, INC. v. LIMELIGHT NETWORKS, INC.

Restatement (Second) of Torts § 491, cmt. c.; see also 57B 

Am. Jur. 2d Negligence § 1138 (2015).

C. Errors in Importing Joint Tortfeasor Liability into 

§ 271(a)

The majority and dissent agree that liability exists 

under traditional principles of vicarious liability, such as 

where a mastermind directs or controls another to perform all steps of a claimed method. But the dissent’s rule 

is far broader—Akamai and the dissent insist that they 

can thrust common law joint tortfeasor liability into 

§ 271(a). The dissent would extend liability to “include[] 

parties who act in concert to collectively perform the 

claimed process pursuant to a common plan, design, or 

purpose.” Dissent at 16. The error of this approach is 

that it attempts to fit a square peg in a round hole: joint 

tortfeasor law and § 271 are fundamentally incompatible. 

To import joint tortfeasor law into § 271(a), Akamai and 

the dissent depart from three indispensable common law 

limits on joint tortfeasor liability.

First, the Restatement is clear that joint tortfeasor liability “includes only situations in which the defendant 

has been personally guilty of tortious conduct.” Restatement (Second) of Torts § 875, cmt. a (1979). Yet personal 

guilt of direct infringement of a method claim under 

§ 271(a) requires performance by the accused of all steps 

recited in the claim. The Restatement (Second) of Torts 

§ 876, cmt. c (1979) explains that “[o]ne who innocently, 

rightfully and carefully does an act that has the effect of 

furthering the tortious conduct or cooperating in the 

tortious design of another is not for that reason subject to 

liability.” Thus, contrary to Akamai’s and the dissent’s 

positions, actors whose innocent actions coordinate to 

cause harm generally are not subject to liability at common law.

Second, the dissent purports to adopt the Restatement’s rule of action in concert. But, according to the 

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Restatement, “[p]arties are acting in concert when they 

act in accordance with an agreement to cooperate in a 

particular line of conduct or to accomplish a particular 

result.” Restatement (Second) of Torts § 876, cmt. a. This 

definition stresses that there must be mutual agreement 

between the parties. Thus, the Restatement describes 

“acting in concert” as a form of “mutual agency.” Id. This 

is consistent with the early patent law treatises that 

limited joint infringement to parties “acting in complicity 

with others,” 3 William C. Robinson, The Law of Patents 

for Useful Inventions § 946 (1890), or parties “cooperat[ing]” in infringement, Albert H. Walker, Textbook of 

the Patent Laws of the United States of America § 406 (4th 

ed. 1904). There is no mutual agency or cooperation when 

parties act independently for their own benefit, such as in 

arms-length seller-customer relationships.

The dissent, meanwhile, would extend liability even 

to arms-length agreements, so long as one party “know[s] 

of th[e] [other] party’s actions.” Dissent at 27. This 

position contravenes both patent law and tort law. The 

Supreme Court in Global-Tech held that “a direct infringer’s knowledge or intent is irrelevant,” 131 S. Ct. at 2065 

n.2, yet the dissent imposes a knowledge requirement. And common tort law requires both parties to 

know the others’ actions to act in concert. See Restatement (Second) of Torts § 876(a) (“a tortious act in concert

with the other or pursuant to a common design with him” 

(emphases added)). One party is “not acting in concert 

with the other” if it “innocently, and carefully, does an act 

which happens to further the tortious purpose of [the] 

[]other.” W. Page Keeton et al., Prosser & Keeton on Torts

§ 46 (1984). Further, as Prosser and Keeton make clear, 

even more is required. “There are even occasional statements that mere knowledge by each party of what the 

other is doing is sufficient ‘concert’ to make each liable for 

the acts of the other; but this seems clearly wrong.” Id. 

(emphasis added). Here, there is no evidence that LimeCase: 09-1372 Document: 316-2 Page: 21 Filed: 05/13/2015
22 AKAMAI TECHNOLOGIES, INC. v. LIMELIGHT NETWORKS, INC.

light’s customers knew what steps Limelight was taking, 

much less evidence that they coordinated further. Thus, 

there was no concert of action. Contrast Dissent at 25

(stating that Limelight and its customers acted “in concert”); id. at 29 (same).

Third, the Restatement describes yet another requirement for concerted action: knowledge of harm. The 

common law sources cited in Akamai’s briefs acknowledge 

that, for joint liability, a defendant needs knowledge of 

damage done or harm caused. See Akamai’s Letter Br. at 

5 (quoting Prosser, § 47, which requires knowing that the 

conduct will “cause damage”); Br. for Resp’ts at 26, Akamai, 134 S. Ct. 2111 (available at 2014 WL 1260422)

(“Akamai’s Supreme Court Br.”) (quoting Warren v. 

Parkhurst, 92 N.Y.S. 725, 727 (N.Y. Sup. Ct. 1904), which 

requires “knowing that the contributions by himself and 

the others . . . w[ould] result necessarily in the destruction 

of the plaintiff’s property” (emphasis and alterations in 

Akamai’s Supreme Court Br.)); id. at 27 (quoting Folsom 

v. Apple River Log-Driving Co., 41 Wis. 602, 610 (1877), 

which found liability for flooding where defendant “had 

notice beforehand of such obstruction, and of the fact that 

its effect, together with the company’s use of the water 

beyond its natural flow, would be to flo[od] the plaintiff’s 

land” (alterations in Akamai’s Supreme Court Br.)); id. at 

28–29 (quoting Wallace, 29 F. Cas. at 80, which imposed 

joint liability where parties “engaged in a common purpose to infringe the patent”). Indeed, this common law 

requirement was statutorily enacted into 35 U.S.C. 

§ 271(b) and (c). See Global-Tech, 131 S. Ct. at 2068 

(holding that both subsections (b) and (c) “require[] 

knowledge [or willful blindness] of the existence of the 

patent that is infringed”).

This is consistent with the description in Prosser & 

Keeton requiring “a common plan or design to commit a 

tortious act,” Prosser & Keeton on Torts § 46. To apply a 

“knowledge of the harm” principle to § 271(a), however, 

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would require knowledge of the patent, knowledge of the 

steps recited in the claims, and knowledge of the risk of 

infringement presented by performance of those steps. 

Adopting such a requirement for liability under § 271(a) 

would be contrary to centuries of settled Supreme Court 

precedent that “a direct infringer’s knowledge or intent is 

irrelevant.” Global-Tech, 131 S. Ct. at 2065 n.2; see also

Hogg v. Emerson, 52 U.S. 587, 607 (1850).

The dissent’s reasoning for eliminating these three 

common law limits on joint tortfeasor liability is that “not 

all joint tortfeasor scenarios are permissible under the 

language of § 271(a).” Dissent at 28. But this simple 

response is wholly insufficient—it does not explain why 

patent law should allow for more expansive joint tortfeasor liability than other areas of law. The common law has 

carefully crafted these limits on tort liability over centuries, in light of fairness and justice. We may not blithely 

toss these limits aside.

The dissent’s rule also leads to several extraordinary 

results. For example, a customer who performs a single 

step of a patented method by merely using a product as 

intended would be jointly and severally liable for direct 

infringement under § 271(a). See Dissent at 10 (“‘whoever . . . uses’ a process for the purposes of infringement 

covers multiple parties who act in concert”). It is nothing 

short of remarkable that while Congress and state legislators express their concern about the vulnerability of 

innocent customers to charges of patent infringement, 

Akamai and the dissent labor to create an unprecedented 

interpretation of existing law to make customers significantly more vulnerable to such charges. This is especially 

troubling given that the customer can be liable even 

without knowing of the patent. Moreover, the dissent’s 

“knowledge of the others’ actions” requirement is an 

illusory protection for customers and other unsuspecting 

parties. Institution of a patent infringement lawsuit 

informs accused infringers of third parties’ actions, so, at 

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24 AKAMAI TECHNOLOGIES, INC. v. LIMELIGHT NETWORKS, INC.

most, requiring knowledge of the others’ actions limits the 

patentee’s recovery to post-suit damages.

The drastic expansion of predatory customer suits is 

not a theoretical concern. Several amici, the White 

House, and other commentators identify numerous instances where patentees have sent demand letters to or 

sued dozens, hundreds, or, in some cases, even thousands 

of unsophisticated downstream users.5 If the law were 

expanded to impose joint and several liability on users of 

a single prior art method step, it would subject swathes of 

innocent actors across diverse industries to these practices.6 Using real patents as examples, amici warn that 

individuals could be liable for patent infringement for so 

little as initiating communication with a doctor or swiping 

5 Br. of Amicus Curiae Elec. Frontier Found. in 

Supp. of Def. at 6–8, Akamai, 692 F.3d 1301 (Fed. Cir. 

Aug. 9, 2011) (available at 2011 WL 3796789) (“EFF Br.”); 

Corrected Br. of Amici Curiae Cisco Sys., Inc. et al. in 

Supp. of Def.-Cross-Appellant at 4–5, Akamai, 692 F.3d 

1301 (Fed. Cir. Aug. 15, 2011) (available at 2011 WL 

4438649) (“Cisco Br.”); Executive Office of the President, Patent Assertion and U.S. Innovation, at 10–12 

(June 2013); Gaia Bernstein, The Rise of the End User in 

Patent Litigation, 55 B.C. L. Rev. 1443, 1443–46 (2014); 

Brian Love & James Yoon, Expanding Patent Law’s 

Customer Suit Exception, 93 B.U. L. Rev. 1605, 1610–11 

(2013).

6 See, e.g., Br. of Amici Curiae Newegg and L.L. 

Bean in Supp. of Pet’r at 18–22, Limelight, 134 S. Ct. 

2111 (Feb. 28, 2014) (available at 2014 WL 880929); Br. of 

Amici Curiae Cargill, Inc. et al. in Supp. of Pet’r Limelight Networks, Inc. at 8–10, Limelight, 134 S. Ct. 2111 

(Mar. 3, 2014) (available at 2014 WL 880935); Cisco Br. at 

4–7.

 

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a debit card.7 Another amici explains that “the hundreds 

if not thousands of contracts in a technology company’s 

supply chain could expose each actor in that supply chain 

to potential patent infringement liability . . . .” Cisco Br. 

at 5. Based on this fact, a patentee could draft “dependent claims whose sole purpose is to add prior art steps 

precisely to increase the patent applicant’s litigation and 

licensing options post-issuance.” Id. at 4.

Finally, the dissent’s position leads to another perverse result: the addition of a claim limitation can actually serve to make more parties liable for infringement. 

Consider a hypothetical in which independent claim 1 

recites a “replicating” step and claim 2, dependent therefrom, adds the limitation of a “tagging” step. The dissent’s rule, which requires only concerted action and does 

not require attribution of the acts of one party to the 

other, would result in a party that performs the tagging 

step but not the replicating step being liable for directly 

infringing dependent claim 2 while not being liable for 

infringing the broader claim from which it depends. This 

conflicts with the “long . . . established” rule that a dependent claim cannot be infringed unless the independent 

claim from which it depends is also infringed. Teledyne 

McCormick Selph v. United States, 558 F.2d 1000, 1004 

(Ct. Cl. 1977); accord Ferring B.V. v. Watson Labs., Inc.-

Fla., 764 F.3d 1401, 1411 (Fed. Cir. 2014) (“Because we 

hold that the asserted independent claims of Ferring’s 

patents are not infringed, the asserted dependent claims 

are likewise not infringed.” (citing cases)).

7 EFF Br. at 5; Br. of Amicus Curiae The Financial 

Services Roundtable in Supp. of Limelight Networks, Inc. 

and Affirmance at 27, Akamai, 692 F.3d 1301 (Fed. Cir. 

Aug. 15, 2011) (available at 2011 WL 7730148).

 

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III. THE FACTS OF THIS CASE

Akamai argues that the facts here are different from 

those in Muniauction, because Limelight provides more 

specific instructions and because it has a contract with its 

customers. Akamai’s Letter Br. at 8–9; see also Corrected 

Br. of Pls.-Appellants at 44, Akamai, 629 F.3d 1311 

(available at 2009 WL 6849543) (“Akamai’s Op. Br.”). 

Limelight argues that the law has not changed since the 

original panel decision. The same precedents that led to 

the original panel decision, most notably BMC and Muniauction, are still binding on this court. Br. for Limelight at 1–2, Akamai, No. 2009-1372 (Fed. Cir. Aug. 18, 

2014). In its original panel briefing, it argued that the 

district court was correct that this case is “indistinguishable” from Muniauction. See Principal and Resp. Br. of 

Def.-Cross-Appellant Limelight Networks, Inc. at 34, 

Akamai, 629 F.3d 1311 (available at 2009 WL 5070030). 

It further argues that even if there is a contract between 

Limelight and its customers, which it contests, this contract “does not compel the customer to do anything.” Id.

at 41.

In this case, there is nothing to indicate that Limelight’s customers are performing any of the claimed 

method steps as agents for Limelight, or in any other way 

vicariously on behalf of Limelight. To the contrary, 

Limelight’s customers direct and control their own use of 

Limelight’s content delivery network (“CDN”). Limelight’s customers serve their own web pages, and decide 

what content, if any, they would like delivered by Limelight’s CDN. Customers sometimes even have Limelight’s 

CDN and competing CDNs simultaneously deliver the 

same content. As such, customers—not Limelight—direct 

and control which CDN delivers each and every object of 

their content. Limelight’s customers do not become 

Limelight’s agents simply because Limelight provides its 

customers a written manual explaining how to operate 

Limelight’s product.

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Moreover, Limelight’s CDN is a service similar to 

Thomson’s on-line auction system in Muniauction, and 

Limelight’s relationship with its customers is similar to 

Thomson’s relationship with the bidders. In both cases, 

customers are provided instructions on use of the service 

and are required to perform some steps of the claimed 

method to take advantage of that service. In Muniauction, the customers performed the step of bidding. Here, 

the customers determine what website content should be 

delivered by Limelight’s CDN and then, allegedly, perform the step of “tagging” that content. Limelight’s 

customers also perform the step of “serving” their own 

web pages. As the district court found, there is “no material difference between Limelight’s interaction with its 

customers and that of Thompson in Muniauction.” Akamai, 614 F. Supp. 2d at 122.

Akamai also argues that the relationship between 

Limelight and its customers compels a finding of infringement because Limelight “contracts out to content 

providers the claim steps that it alone does not perform.” 

Akamai’s Op. Br. at 40. This assertion stems from Limelight’s standard form contract that, according to Akamai, 

“obligates content providers to perform the claim steps of 

tagging the embedded objects and serving the tagged page 

so that requests for the embedded objects resolve to 

Limelight’s network instead of the content provider’s.” Id. 

For this argument, Akamai relies on the statement in 

BMC that “[a] party cannot avoid infringement . . . simply 

by contracting out steps of a patented process to another 

entity,” 498 F.3d at 1381. 

Akamai’s reliance on this statement is misplaced. As 

discussed above, Limelight’s customers decide what 

content, if any, they choose to have delivered by Limelight’s CDN and only then perform the “tagging” and 

“serving” steps. The form contract does not obligate

Limelight’s customers to perform any of the method steps. 

It merely explains that customers will have to perform 

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28 AKAMAI TECHNOLOGIES, INC. v. LIMELIGHT NETWORKS, INC.

the steps if they decide to take advantage of Limelight’s 

service. Because the customers were acting for their own 

benefit, Limelight is not vicariously liable for the customers’ actions. See BMC, 498 F.3d at 1379 (holding that 

liability exists only where the accused infringer has 

“someone else carry out one or more of the claimed steps 

on its behalf”); Muniauction, 532 F.3d at 1329 (“mere 

‘arms-length cooperation’ will not give rise to direct 

infringement by any party”) (quoting BMC, 498 F.3d at 

1381).

In the present case, the asserted claims were drafted 

so as to require the activities of both Limelight and its 

customers for a finding of infringement. Thus, Akamai 

put itself in a position of having to show that the allegedly 

infringing activities of Limelight’s customers were attributable to Limelight. Akamai did not meet this burden 

because it did not show that Limelight’s customers were 

acting as agents of or otherwise contractually obligated to 

Limelight or that they were acting in a joint enterprise 

when performing the tagging and serving steps. Accordingly, we affirm the district court’s grant of Limelight’s 

motion for JMOL of non-infringement under § 271(a).

IV. CONCLUSION

For the foregoing reasons, this court affirms the district court’s grant of Limelight’s motion for JMOL of noninfringement of the ’703 patent.

Limelight argues as an alternative ground for affirmance that Akamai presented no substantial evidence 

that Limelight or its customers actually performed the 

tagging limitation as properly construed. Because we find 

that the district court properly granted JMOL of noninfringement on the ground stated, we need not and do not 

address this argument. Likewise, we do not reach Limelight’s conditional cross-appeal of the damages award 

alleging that Akamai failed to present economic proof of a 

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AKAMAI TECHNOLOGIES, INC. v. LIMELIGHT NETWORKS, INC. 29

causal link between Limelight’s infringement and any 

Akamai lost sales.

We also confirm our previously reinstated affirmance 

of the district court’s judgment of noninfringement of 

the ’413 and ’645 patents.

AFFIRMED

Case: 09-1372 Document: 316-2 Page: 29 Filed: 05/13/2015
United States Court of Appeals 

for the Federal Circuit ______________________

AKAMAI TECHNOLOGIES, INC.,

THE MASSACHUSETTS INSTITUTE OF 

TECHNOLOGY,

Plaintiffs-Appellants

v.

LIMELIGHT NETWORKS, INC.,

Defendant-Cross-Appellant

______________________

2009-1372, 2009-1380, 2009-1416, 2009-1417

______________________

Appeals from the United States District Court for the 

District of Massachusetts in Nos. 06-CV-11585, 06-CV11109, Judge Rya W. Zobel.

______________________

MOORE, Circuit Judge, dissenting.

Today the majority holds that the actions of multiple 

parties can only result in direct infringement of a method 

claim in three circumstances: in a principal-agent relationship, in a contractual arrangement, or in a joint 

enterprise functioning as a form of mutual agency. It 

divorces patent law from mainstream legal principles by

refusing to accept that § 271(a) includes joint tortfeasor 

liability. The majority’s rule creates a gaping hole in 

what for centuries has been recognized as an actionable 

form of infringement. It claims that this result is mandated by the statute. I do not agree. The single entity 

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2 AKAMAI TECHNOLOGIES, INC. v. LIMELIGHT NETWORKS, INC.

rule promulgated in BMC and Muniauction is a recent 

judicial creation inconsistent with statute, common law, 

and common sense. For centuries, the concerted actions 

of multiple parties to infringe a patent gave rise to liability. The plain language of § 271(a) codified this joint 

infringement. To construe that language otherwise would 

permit identical language in the statute to have inconsistent meanings. Congress meant to and did codify 

liability for joint infringement. It did not, as the majority 

suggests, purposefully do away with a broad swath of 

recognized forms of liability for infringement. I respectfully dissent from the majority’s decision to interpret 

§ 271(a) in a manner that condones the infringing conduct

in this case. 

Without the innovative technology protected by the 

patent-in-suit, the Internet as we know it would not exist. 

In the mid-1990s, the Internet was exploding. Ever 

increasing numbers of users were sharing increasingly 

bandwidth-heavy information, often at great distances. 

From text to photos to music and videos, users were 

placing exponentially greater pressure on the infrastructure of the Internet. Congestion and interruptions in 

service were standard.

Mirroring, where an entire website is replicated on 

multiple servers in multiple locations, was a known 

solution to some of these problems. However, mirroring

came with problems of its own. Mirroring was not scalable, and content providers had less control over mirrored 

data stored on servers in distant locations. Because of the 

overhead required to synchronize mirrored websites at 

multiple locations, mirroring was inefficient for websites

with dynamic information.

Dr. Tom Leighton, a professor of theoretical mathematics at MIT, and Danny Lewin, his research assistant, 

solved these problems. They developed a scalable netCase: 09-1372 Document: 316-2 Page: 31 Filed: 05/13/2015
AKAMAI TECHNOLOGIES, INC. v. LIMELIGHT NETWORKS, INC. 3

work of mirrored, geographically distributed servers for 

delivering content (content delivery network or CDN). To 

direct requests for this content, they developed a domain 

name system that could intelligently select a suitable 

CDN server from which the user could obtain the requested content. And they developed a method by which content providers could “tag” content to be delivered by the 

CDN, rather than their own servers. Using their invention, a content provider like ESPN could serve the text of 

its website (with news articles updated in real time) from 

its own servers and tag static, bandwidth-heavy content 

(such as photos and videos accompanying a news article)

to be served by the CDN, reducing the burden on ESPN’s 

server. Dr. Leighton and Mr. Lewin’s invention promised

efficient, scalable delivery of tagged content while maintaining a content provider’s flexibility and control over 

other content.

To protect their innovation, Dr. Leighton and Mr. 

Lewin patented their invention. They then founded 

Akamai, the exclusive licensee of the patent-in-suit, U.S. 

Patent No. 6,108,703. Akamai was an immediate success, 

and its dramatically improved method of delivering 

content was compared to “great historical shifts—

discoveries of better, faster ways—like the invention of 

Arabic numerals, or the development of seafaring.” Paul 

Spinrad, The New Cool: Akamai Overcomes the Internet’s 

Hot Spot Problem, WIRED (Aug. 1999), available at

http://archive.wired.com/wired/archive/7.08/akamai_pr.ht

ml. 

In response to Akamai’s success, competitors began 

copying Akamai’s methods of distributing content. Limelight, founded a few years after Akamai, is one such 

competitor. A jury found that Limelight, in collaboration

with its content provider customers, practices every step 

of the methods disclosed in four claims of the ’703 patent. 

For example, of the four steps of claim 34 of the ’703 

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4 AKAMAI TECHNOLOGIES, INC. v. LIMELIGHT NETWORKS, INC.

patent, Limelight performs every step save one: the 

“tagging” step. This step is performed by Limelight’s 

customers, who tag the content to be hosted and delivered 

by Limelight’s CDN. Limelight instructs its customers 

how to tag, and employees are on call if its customers 

require additional assistance. Moreover, Limelight requires all of its customers to sign a standard contract. 

The contract delineates the steps that must be performed 

by these customers if they use the Limelight service—

steps that include tagging content. When Limelight’s 

content delivery customer chooses to use Limelight’s CDN 

to deliver web content to Internet users, it must tag 

content. It has no choice: if it wishes to use the product, it 

must tag content. Limelight itself then performs all of the 

other steps of Akamai’s patent claims. Thus, every time 

Limelight’s service is used, all the claim steps of Akamai’s 

patent are performed as part of the Limelight CDN service. 

When Dr. Leighton and Mr. Lewin patented their invention, they expected our legal system to protect their 

intellectual property. For all of history, a company that 

did what Limelight had done would be liable for patent 

infringement. Limelight performed all but one step of a 

patented method, and Limelight directed its customers to 

perform that final step. Both Limelight and its customers 

obtained the economic benefits of performing all of the 

steps of the claimed patent—namely, faster, more efficient delivery of tagged content coupled with control and 

flexibility over untagged content. To say Limelight has 

not committed the tort of patent infringement is inconsistent with the common law, the plain language of the 

Patent Act, and centuries of patent law that preceded

BMC and Muniauction.

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AKAMAI TECHNOLOGIES, INC. v. LIMELIGHT NETWORKS, INC. 5

I. The Creation of the Single Entity Rule and the Direction or Control Test

The majority’s ruling today rests on its application of 

one rule—the single entity rule—and its interpretation of 

another—the direction or control test. Before explaining 

why the majority’s view of these rules are inconsistent 

with the statute, it is helpful to briefly explain the manner by which they came into being. 

BMC treated the single entity rule as if it were a first 

principle, proclaiming that “[i]nfringement requires, as it 

always has, a showing that a defendant has practiced 

each and every element of the claimed invention.” BMC 

Res., Inc. v. Paymentech, L.P., 498 F.3d 1373, 1380 (Fed. 

Cir. 2007). It concluded—without analysis—that the 

single entity rule was derived from the use of the term 

“whoever” in § 271(a). Id. To support this seemingly ageold proposition, BMC cited to the Supreme Court’s holding in Warner-Jenkinson Co. v. Hilton Davis Chemical 

Co., 520 U.S. 17, 40 (1997), that the doctrine of equivalents should be performed on an element-by-element 

basis. BMC, 498 F.3d at 1380. As commentators have 

noted, Warner-Jenkinson’s discussion of the all elements 

rule does not support the much narrower proposition that 

BMC attributed to it. See, e.g., W. Keith Robinson, No 

“Direction” Home: An Alternative Approach to Joint 

Infringement, 62 AM. U. L. REV. 59, 86 (2012); Damon 

Gupta, Virtually Uninfringeable: Valid Patents Lacking 

Protection Under the Single Entity Rule, 94 J. PAT. &

TRADEMARK OFF. SOC’Y 61, 63 n.32 (2012); see also Dennis 

Crouch, Joint Infringement: When Multiple Actors Work 

in Concert, Patently–O (Apr. 14, 2011),

http://www.patentlyo.com/patent/2011/04/jointinfringement-when-multiple-actors-work-in-concert.html

(“In several post-1952 cases, the Supreme Court has 

stated that an invention must actually be infringed—i.e., 

practiced—before someone can be liable for indirect 

infringement. However, in those cases, the Supreme 

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6 AKAMAI TECHNOLOGIES, INC. v. LIMELIGHT NETWORKS, INC.

Court did not state that the actual infringement must be 

performed by a single entity.”). Further, as the amici and 

commentators have noted, there does not appear to be any 

precedential support for the single entity rule. Brief of 

Amicus Curiae Pharmaceutical Research and Manufacturers of America at 8, Akamai Techs., Inc. v. Limelight 

Networks, Inc., 692 F.3d 1301 (Fed. Cir. 2012) (en banc) 

(No. 09-1372) (“[T]here is no longstanding or properly 

considered rule that requires all the steps of a method 

claim to be performed by a single actor, and there is a 

significant body of law that holds otherwise.”) (“Pharmaceutical Research Amicus Brief”); Brief of Amicus Curiae 

Biotechnology Industry Organization at 23, Akamai, 692 

F.3d 1301 (No. 09-1372) (“Nothing in Supreme Court 

jurisprudence indicates that the predicate act of direct 

infringement can only be undertaken by a single entity.”)

(“Biotechnology Amicus Brief”); W. Keith Robinson, No 

“Direction” Home: An Alternative Approach to Joint 

Infringement, 62 AM. U. L. REV. 59, 86 (2012) (noting that 

“none of these cases [relied on by BMC] explicitly state 

that ‘a single entity’ must perform each and every step of 

a claimed method to be a direct infringer.”); Brett M. 

Jackson, Bridging the (Liability) Gap: The Shift Toward 

§ 271(b) Inducement in Akamai Represents a Partial 

Solution to Divided Infringement, 54 B.C. L. REV. 2127, 

2151 (2013) (discussing the “‘single entity’ rule announced 

in BMC”).

With scant analysis, the single entity rule was born. 

To the extent there was any confusion about the use of

the term “a defendant” in BMC, the court’s Muniauction 

decision made clear that “direct infringement requires a 

single party to perform every step of a claimed method.” 

Muniauction, Inc. v. Thomson Corp., 532 F.3d 1318, 1329

(Fed. Cir. 2008) (emphasis added). Both BMC and Muniauction explain that whether the combined acts of 

multiple parties should be attributed to a single entity is 

determined by the “direction or control” test—“where the 

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AKAMAI TECHNOLOGIES, INC. v. LIMELIGHT NETWORKS, INC. 7

actions of multiple parties combine to perform every step

of a claimed method, the claim is directly infringed only if 

one party exercises ‘direction or control’ over the entire 

process such that every step is attributable to the controlling party, i.e. the ‘mastermind.’” Muniauction, 532 F.3d 

at 1329 (quoting BMC). 

Neither of these cases supports the claim that the 

single entity rule is some longstanding, well-accepted 

principle. A host of amici and commentators agree that 

BMC and Muniauction’s pronouncement of the single 

entity rule changed the law, vitiated broad classes of 

patents, and created a gaping loophole in infringement 

liability. Brief of Amicus Curiae Boston Patent Law

Association at 1, Akamai, 692 F.3d 1301 (No. 09-1372)

(“[The single entity rule] improperly and unnecessarily 

renders worthless an entire class of interactive method 

patents and will undermine the public’s confidence in 

patents and in the patent system as a whole.”); Brief of 

Amicus Curiae Cascades Ventures, Inc. at 5–6, 11, Akamai, 692 F.3d 1301 (No. 09-1372) (“[BMC and Muniauction] have changed the law to create a gaping hole in 

liability for patent infringement” and the Akamai panel 

decision has “destroyed thousands of duly issued patent 

claims.”) (“Cascades Amicus Brief”); Brief of Amicus 

Curiae Myriad Genetics, Inc. at 2–3, Akamai, 692 F.3d 

1301 (No. 09-1372) (noting that strict application of the 

single entity rule “encourages collusion among collaborating parties to escape infringement liability[,] eviscerates a 

large number of method patent claims in the field of 

personalized medicine, as well as many other fields, and 

significantly weakens the U.S. patent system”) (“Myriad 

Amicus Brief”); Biotechnology Amicus Brief at 9–10 

(“[T]his Court’s single entity rule invites would-be infringers to circumvent a particularly valuable subset of 

biotechnology patents by ‘dividing up’ steps of patented 

methods for separate practice, and avoiding the kinds of 

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8 AKAMAI TECHNOLOGIES, INC. v. LIMELIGHT NETWORKS, INC.

formal legal relationships that were only recently established by this Court as a predicate to infringement liability.”); Stacie L. Greskowiak, Joint Infringement After

BMC: The Demise of Process Patents, 41 LOY. U. CHI. L.J.

351, 403 (2010) (“Without judicial recourse, the ‘direction 

or control’ standard will render thousands of socially 

valuable and otherwise valid process patents unenforceable.”); Alice Juwon Ahn, Finding Vicarious Liability in 

U.S. Patent Law: The “Control or Direction” Standard for 

Joint Infringement, 24 BERKELEY TECH. L.J. 149, 171

(2009) (“[M]any thousands of patents may become worthless under the stringent ‘control or direction’ standard set 

forth in the Muniauction decision.”); Long Truong, After 

BMC Resources, Inc. v. Paymentech, L.P.: Conspiratorial 

Infringement as a Means of Holding Joint Infringers 

Liable, 103 NW. U. L. REV. 1897, 1899 (2009) (“The loophole [created by BMC] is a serious one. It encourages 

potential infringers of process patents to enter into conspiracies to circumvent infringement liability by dividing 

steps among the parties so long as there is no controlling 

or directing party.”); Dolly Wu, Joint Infringement and 

Internet Software Patents: An Uncertain Future?, 91 J.

PAT. & TRADEMARK OFF. SOC’Y 439, 441 (2009) (“The 

[Muniauction] decision creates a catch-22 situation because it is unlikely for vicarious liability relationships to 

exist across the Internet. Due to Muniauction, not only 

are many Internet software patents now unenforceable, 

but many other network and communication patents may 

also be unenforceable.”). 

That many patentees crafted their patent claims in a 

manner that is incapable of being infringed belies the 

proposition that there was a long-standing single entity 

requirement for direct infringement. I do not agree with 

the majority that this patent, and the thousands of other 

patents across many different industries, drafted in a 

manner which contemplated joint infringement liability, 

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AKAMAI TECHNOLOGIES, INC. v. LIMELIGHT NETWORKS, INC. 9

are “poorly-drafted.” Maj. at 17. Instead, we have 

changed the rules on these folks. Clarity is not a virtue 

we can claim in this particular scenario. 

II. Joint Infringement Liability Under § 271(a)

Section 271 defines the requirements for infringement. This case is first, last, and entirely about statutory 

construction. Section 271(a) provides that: “whoever 

without authority makes, uses, offers to sell, or sells any 

patented invention, within the United States or imports 

into the United States any patented invention during the 

term of the patent therefor, infringes the patent.” 35 

U.S.C. § 271(a). All agree that infringement of a process 

claim requires each claimed step to be performed—that is 

how the process is “use[d].” Nothing about joint infringement changes or undermines the all elements rule. For 

infringement to occur, all the elements or steps must be 

performed. The dispute here is about who must perform 

those steps. That dispute centers around the meaning of 

“whoever.” 

“Whoever,” as used in § 271(a), encompasses multiple 

entities. Dictionaries define “whoever” in the plural as 

“[w]hatever person or persons.” Principal Brief for Plaintiff-Appellant Akamai on Rehearing En Banc at 15,

Akamai, 692 F.3d 1301 (No. 09-1372) (quoting American 

Heritage College Dictionary 1540 (3d ed. 1997)); Brief of 

Amicus Curiae AIPLA at 11, Limelight Networks, Inc. v. 

Akamai Techs., Inc., 134 S. Ct. 2111 (2014) (No. 12-786)

(quoting American Heritage Dictionary of the English 

Language (4th ed. 2000)) (“AIPLA Amicus Brief”). The 

Dictionary Act states that “words importing the singular 

include and apply to several persons, parties, or things,” 

and it expressly defines “whoever” as including plural 

entities: “the words ‘person’ and ‘whoever’ include corporations, companies, associations, firms, partnerships, 

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10 AKAMAI TECHNOLOGIES, INC. v. LIMELIGHT NETWORKS, INC.

als.” 1 U.S.C. § 1. By its plain language, the phrase 

“whoever . . . makes, uses, offers to sell, or sells any 

patented invention . . . infringes the patent” means “any 

person or persons who make, use, offer to sell, or sell any 

patented invention infringe the patent.” 

The word “whoever” appears in other sections of the 

Patent Act, and in each case the word “whoever” expressly 

includes the collective actions of multiple persons. Identical terms are presumed to have the same meaning within 

a statute, even if the terms appear in different sections. 

Sullivan v. Stroop, 496 U.S. 478, 484 (1990) (“[T]he normal rule of statutory construction [is] that identical words 

used in different parts of the same act are intended to 

have the same meaning.”); see also Antonin Scalia & 

Bryan A. Garner, Reading Law: The Interpretation of 

Legal Texts 170–73 (2012) (“A word or phrase is presumed 

to bear the same meaning throughout a text . . . . Th[is] 

presumption . . . applies also when different sections of an 

act or code are at issue.”). 35 U.S.C. § 101 states that 

“whoever invents or discovers any new and useful process 

. . . may obtain a patent therefor . . . .” All agree that 

“whoever” in § 101 includes joint inventors. See 35 U.S.C. 

§ 116(a); see also 35 U.S.C. §§ 161, 171. One can be a joint 

inventor, and thus within the meaning of “whoever invents,” as long as he contributes to the conception of the 

invention, even if he does not conceive of the entire invention. Vanderbilt Univ. v. ICOS Corp., 601 F.3d 1297, 

1303 (Fed. Cir. 2010); Eli Lilly & Co. v. Aradigm Corp., 

376 F.3d 1352, 1359 (Fed. Cir. 2004). It follows, then, 

that “whoever . . . uses” a process for the purposes of 

infringement covers multiple parties who act in concert to 

collectively perform the claimed process, even though they 

may not individually practice each step. 

The majority gives little consideration to the text of 

the statute, relegating its discussion of “whoever” to a 

footnote. It does not consider principles of statutory 

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AKAMAI TECHNOLOGIES, INC. v. LIMELIGHT NETWORKS, INC. 11

construction or attempt to reconcile its construction with 

the other uses of “whoever” in the same statute. The 

majority posits that the fact that whoever is plural means 

only that more than one entity can be liable for patent 

infringement. This construction assigns no weight to the 

plural form because the same would be true if the singular were used. For example, if the statute read “one who 

uses” a patented invention, all would agree that two 

people performing each step of the patented process would 

each be liable for infringement. No one would claim that 

once the first person infringed, the second could not be 

liable for infringement. The majority’s construction 

makes no sense and is inconsistent with the statute’s use 

of “whoever” in 35 U.S.C. §§ 101, 161, and 171, which all 

undeniably reference joint inventors, meaning multiple 

parties acting together. 

The plain language and contextual analysis compel the 

conclusion that “whoever” within the context of § 271(a) 

includes joint infringers—multiple entities acting in 

concert pursuant to a common plan or purpose (joint 

tortfeasors). Moreover, the presumption against ineffectiveness supports construing “whoever” to include joint 

infringement. If “language is susceptible of two constructions, one of which will carry out and the other defeat its 

manifest object, the statute should receive the former 

construction.” Antonin Scalia & Bryan A. Garner, Reading Law: The Interpretation of Legal Texts 63 (2012)

(quoting Citizen Bank of Bryan v. First State Bank, 580 

S.W.2d 344, 348 (Tex. 1979)) (alterations omitted). Construing “whoever” as the majority does creates a “gaping 

loophole” in our infringement law that sanctions infringing activity and “renders issued and future patents in 

important technologies virtually unenforceable.” AIPLA 

Amicus Brief at 9. See also Biotechnology Amicus Brief at 

13 (“[B]oth common sense and the patent law’s purpose 

would be defeated if joint actors were allowed to divide up 

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12 AKAMAI TECHNOLOGIES, INC. v. LIMELIGHT NETWORKS, INC.

the practice of a patented invention in circumvention of 

the patentee’s rights.”); Myriad Amicus Brief at 11 (“The 

Federal Circuit’s recent decisions on so-called ‘joint infringement’ have taken a restrictive approach and, in so 

doing, have created a loophole for would-be infringers.”); 

Damon Gupta, Virtually Uninfringeable: Valid Patents 

Lacking Protection Under the Single Entity Rule, 94 J. 

PAT. & TRADEMARK OFF. SOC’Y 61, 68, 74 (2012) (explaining that the Federal Circuit’s single entity rule “has 

created an incongruous result—some patents are virtually 

uninfringeable. . . . This creates a loophole where a defendant can collaborate with others to collectively perform 

every step of the patented process and avoid liability for 

infringement.”).

For example, consider the following scenario. Party A

intentionally induces party B to perform each and every 

step of a method claim. Unquestionably, party B is a 

direct infringer under § 271(a) and party A is an inducer 

under § 271(b). Switching the facts only slightly, assume 

that party A performs the first step in the claimed method 

and then, with the same knowledge and intent, induces 

party B to perform the remaining steps. Under the majority’s rule, neither party is liable, even though the harm to 

the patentee remains the same. Party A is not even liable 

as an inducer because, under the single entity rule, no 

direct infringement has occurred. Limelight, 134 S. Ct. at 

2117 (“[W]here there has been no direct infringement, 

there can be no inducement of infringement.”). To apply 

the majority’s construction “would be rendering the law in 

a great measure nugatory, and enable offenders to elude 

its provisions in the most easy manner.” The Emily & the 

Caroline, 22 U.S. (9 Wheat.) 381 (1824) (Thompson, J.). 

Indeed, the Supreme Court recognized that the loophole 

may have arisen from “the possibility that the Federal 

Circuit erred by too narrowly circumscribing the scope of 

§ 271(a).” Limelight, 134 S. Ct. at 2119. 

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The majority claims that this gaping hole in liability, 

which the majority never defends, and which all agree 

makes no sense, was “Congress’ deliberate choice.” According to the majority, “Congress carefully crafted subsections (b) and (c)” and intentionally “removed joint-actor 

patent infringement liability.” Maj. at 10–11. The majority recognizes that “[a]t the time, the common law contained myriad other theories of infringement, such as, for 

example, those in Peerless and Solva. In enacting § 271(b)

and (c), Congress cleared away the morass of multi-actor 

infringement.” Maj. at 11 (full cites omitted).1 It has 

been generally understood that with regard to infringement, the 1952 Patent Act was not meant to make sweeping changes to the scope of liability, but rather to codify

existing infringement liability and restore notions of 

infringement which had been curtailed by the Supreme 

Court’s decisions in Mercoid Corp. v. Mid-Continent 

Investment Co., 320 U.S. 661 (1944), and Mercoid Corp. v. 

Minneapolis-Honeywell Regulator Co., 320 U.S. 680 

(1944). 

The majority never explains why Congress would intentionally do away with joint infringement liability and 

create what is universally recognized as a gaping hole in 

liability. No party or amici defends as logical the rule 

1 Even amici who suggest that § 271(a) does not include joint infringement admit that such a result was 

likely never intended by Congress. See, e.g., Brief of 

Amicus Curiae United States at 14, Limelight, 134 S. Ct. 

2111 (No. 12-786) (“As a matter of patent policy, there is 

no obvious reason why a party should be liable for inducing infringement when it actively induces another party 

to perform all the steps of the process, but not liable when 

it performs some steps and induces another party to 

perform the rest. . . . The statutory gap is unfortunate.”) 

(“US Amicus Brief”).

 

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which the majority says Congress intentionally adopted: 

that when one induces another to perform the steps of a 

patented method both parties are liable; however, when 

one performs some of the steps and induces another to 

perform the remaining steps, nobody is liable. The harm 

to the patentee is identical in either case—the entire 

method has been performed—and the joint tortfeasors 

have received the economic benefit of that patented

method. 

The majority’s primary criticism of interpreting “whoever” in § 271(a) to include joint infringers is that doing so 

would render §§ 271(b) and (c) superfluous. This is simply 

wrong. Sections 271(b) and (c) would still apply in situations where § 271(a) would not. AIPLA Amicus Brief at 

17–20. Consider the same scenario discussed previously—where one party induces another to perform all steps 

of a claimed method. That party has undisputedly infringed under § 271(b). It is not, however, liable for direct 

infringement under § 271(a) because it has not performed 

any step of the claimed method. Section 271(a), by its 

own terms, does not apply to an entity that does not 

perform any step of a patented method, because that 

party would not be one of the person or persons who 

jointly “uses” the method within the meaning of the 

statute.2 See NTP, Inc. v. Research In Motion, Ltd., 418 

2 It is an unassailable truism that an entity who 

does not perform any method steps is not using the method, not individually and not jointly. The majority also 

claims that this unremarkable definition of “use” would be 

at odds with common law tort principles because it would 

exclude inducers who encourage another’s use without 

themselves performing steps. But isn’t this exactly what 

Congress did cover in § 271(b)? I am not sure how Congress’ choice to divide joint tortfeasor acts giving rise to 

 

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F.3d 1282, 1318 (Fed. Cir. 2005) (“Because a process is 

nothing more than the sequence of actions of which it is 

comprised, the use of a process necessarily involves doing 

or performing each of the steps recited.”); see also AIPLA 

Amicus Brief at 18 (“Section 271(a) does not apply to an 

entity that performs no steps of a patented method.”); 

Bauer & Cie v. O’Donnell, 229 U.S. 1, 10–11 (1913) (“The 

right to use is a comprehensive term and embraces within 

its meaning the right to put into service any given invention.”). As this example demonstrates, §§ 271(b) and (c) 

are not at all rendered superfluous. The majority’s claim 

that I have “manufactured a single case” so as not to 

“render § 271(b) superfluous” is confusing. Sections

271(b) and (c) would continue to apply and be the exclusive avenue for liability where the inducer or contributor 

did not perform any of the steps themselves. Rather than 

being an off-the-mark single example, this example is the 

fact pattern of every §§ 271(b) and (c) case ever decided. 

No case ever decided under § 271(b) or (c) would come out 

differently, nor would any of those fact patterns give rise 

to § 271(a) liability, under my construction. Nothing is 

superfluous. 

The plain language of § 271(a) and the accompanying 

sections of the Patent Act make clear that “whoever . . . 

uses” a process includes joint infringers just as “whoever 

invents” includes joint inventors. And despite the majority’s pronouncement, this standard is not limited to parties 

acting as part of a principal-agent relationship, a contractual arrangement, or a joint enterprise. The statutory 

language, the common law, and our case law are not so 

limiting. Joint infringement encompasses an infringer 

who performs some claim steps and directs or controls 

liability among the three sections (a), (b), and (c) is “untenable.” Maj. at 9. 

 

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16 AKAMAI TECHNOLOGIES, INC. v. LIMELIGHT NETWORKS, INC.

another to perform the remainder of the claimed process

and it includes parties who act in concert to collectively 

perform the claimed process pursuant to a common plan, 

design, or purpose. Liability for such multi-actor joint 

infringement was present and widely recognized in the 

common law prior to the 1952 Patent Act, and continues 

to be present in § 271(a). 

The majority suggests that its construction is correct 

despite the fact that it renders the use of “whoever” in the 

Patent Act internally inconsistent and without considering, or even admitting, that it creates a gaping hole in 

liability that had not previously existed in the common 

law. Instead, the majority claims that this was purposeful and intentional by Congress because, in 1952, Congress sought to do away with all commonly recognized 

forms of joint infringement except that codified in 

§§ 271(b) and (c). Section 271(a)’s use of “whoever” expressly includes joint infringement as §§ 101, 161, and 

171’s use of “whoever” includes joint invention. The plain 

language of the statute indicates that Congress chose to 

divide joint tortfeasor acts giving rise to liability among 

the three sections (a), (b), and (c). This construction gives 

meaning to all the words in the statute, interprets the 

word “whoever” consistently, and reflects Congress’ codification of the state of liability for infringement prior to the 

creation of the 1952 Patent Act. 

III. The Common Law Supports § 271(a) 

Joint Infringement Liability

The Supreme Court observed in Aro Manufacturing 

Co. v. Convertible Top Replacement Co., 365 U.S. 336, 342 

(1961) that “§ 271(a) of the new Patent Code, which 

defines ‘infringement,’ left intact the entire body of case 

law on direct infringement.” The common law prior to the 

1952 Patent Act recognized joint liability for patent 

infringement in a broader set of circumstances than 

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proposed today by the majority, such as where one party 

directs or controls the actions of another to infringe a 

patent, or where two parties act in concert to perform the 

claimed method steps pursuant to a common goal, plan, or 

purpose. As summarized by Robinson’s famous patent 

treatise, “[a]n act of infringement is committed by making, using, or selling the patented invention without 

authority from the owner . . . or by acting in complicity 

with others under any cover or pretence the practical 

effect of which is an invasion of the monopoly created by 

the patent. All who perform or who unite in the performance of an act of infringement, by any of these methods, 

may be sued jointly and severally.” 3 William C. Robinson, The Law of Patents for Useful Inventions § 946 (1890)

(“Robinson”). Similarly, another treatise explained that 

“[w]hoever directs or requests another to infringe a patent, is himself liable to an action for the resulting infringement,” and “[w]here several persons co-operate in 

any infringement, all those persons are liable therefor as 

contributors thereto.” Albert H. Walker, Textbook of the 

Patent Laws of the United States of America (4th ed. 1904)

(“Walker”).3

3 Joint infringement is not a “relatively new problem.” US Amicus Brief at 31; see also id. at 14 (“[T]he 

current provisions of Section 271 do not deal adequately 

with the relatively new phenomenon in which multiple 

parties collectively practice the steps of a patented method.”). From the earliest patent treatises throughout the 

legislative history of the 1952 Patent Act and continuing 

to the thousands of current patents whose claims are 

drafted to cover joint infringement, the practice of multiple parties acting in concert to perform the steps of a 

patented method has been known and cognizable. See 

Walker, supra; Robinson, supra (both acknowledging that 

 

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Several of the pre-1952 cases cited by the parties recognize joint infringement liability. In York & Maryland

Line Railroad Co. v. Winans, the Supreme Court held that 

a company that owned the rails on which a different 

company operated infringing cars for both companies’ 

profits was liable for infringement because it was “a 

principal, cooperating with another corporation, in the 

infliction of a wrong, and is directly responsible for the 

if “several persons cooperate in any infringement” they 

are all liable); Contributory Infringement: Hearings on 

H.R. 3866 Before Subcomm. No. 4 of the House Comm. on 

the Judiciary, 81st Cong. 3 (1949) (statement of G. Rich) 

(“[W]hen two people combine and infringe a patent in 

some way or other, they are joint tort feasors, and it so 

happens that patents are often infringed by people acting 

in concert, either specifically or by implication.”); Contributory Infringement in Patents: Hearings Before Subcomm. on Patents, Trade-marks, and Copyrights of the H. 

Comm. on the Judiciary, 80th Cong. 5 (1948) (statement 

of G. Rich on behalf of the New York Patent Law Association) (arguing in favor of adoption of the 1952 Patent Act 

in order to establish liability where a patented method is 

performed by two or more persons acting in concert: “a 

new method of radio communication may involve a change 

in the transmitter and a corresponding change in the 

receiver. To describe such an invention in patent claims, 

it is necessary either to specify a new method which 

involves both transmitting and receiving, or a new combination of an element in the receiver and an element in the 

transmitter . . . The recent decisions of the Supreme Court 

appear to make it impossible to enforce such patents in 

the usual case where a radio transmitter and a radio 

receiver are owned and operated by different persons.”). 

Joint infringement is not a new problem nor is it one that 

escaped Congress’ attention in 1952. 

 

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resulting damage.” 58 U.S. 30, 40 (1854). Similarly, in 

Jackson v. Nagle, a contractor that performed certain 

infringing steps and a subcontractor that performed the 

remaining infringing steps were held liable as “joint 

infringers.” 47 F. 703 (C.C.N.D. Cal. 1891).4 See also 

Thomson-Houston Elec. Co. v. Ohio Brass Co., 80 F. 712, 

721 (6th Cir. 1897) (“An infringement of a patent is a tort 

analogous to trespass or trespass on the case. From the 

earliest times, all who take part in a trespass, either by 

actual participation therein or by aiding and abetting it, 

have been held to be jointly and severally liable for the 

injury inflicted. . . . If this healthful rule is not to apply to 

trespass upon patent property, then, indeed, the protection which is promised by the constitution and laws of the 

United States to inventors is a poor sham.”); New Jersey 

Patent Co. v. Schaeffer, 159 F. 171, 173 (C.C.E.D. Pa. 

1908) (“Where an infringement of a patent is brought 

about by concert of action between a defendant and complainants’ licensee, all engaged directly and intentionally 

become joint infringers.”); Wallace v. Holmes, 29 F. Cas. 

74, 80 (C.C.D. Conn. 1871) (If, “in actual concert,” one 

party consents to manufacture a first part of a claimed 

combination, and another party makes the second part, 

both “are tort-feasors, engaged in a common purpose to 

4 The majority discounts Jackson and other pre1952 cases on the basis that they did not deal with method claims. The language of the patent statute draws no 

distinctions between method and machine claims to 

indicate that Congress intended joint tortfeasor concepts 

to be incorporated into infringement liability when machine claims are at issue, but not when method claims are 

at issue. These cases indicate that concerted action 

amounted to joint infringement and was actionable at the 

time. 

 

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infringe the patent, and actually, by their concerted 

action, producing that result.”). 

Two other pre-1952 cases from the Seventh Circuit 

confirm the understanding that the concerted actions of 

two different parties can result in direct infringement of a 

method claim. In Peerless Equipment Co. v. W. H. Miner, 

Inc., the defendant manufacturer performed all but the 

last step of the claimed method, which was performed by 

the defendant’s customer. 93 F.2d 98, 105 (7th Cir. 1937). 

Despite the divided infringement scenario, the Seventh 

Circuit found the defendant liable for contributory infringement. Id. Similarly, in Solva Waterproof Glue Co. 

v. Perkins Glue Co., the defendant was held liable for 

contributory infringement where the defendant’s customer performed one step of the two-step process. 251 F. 64, 

73 (7th Cir. 1918). For the defendants in both cases to be 

liable for contributory infringement, there must have 

been some underlying direct infringement. Limelight, 134 

S. Ct. at 2117 (“[O]ur case law leaves no doubt that inducement liability may arise ‘if, but only if, [there is] . . . 

direct infringement.’”) (quoting Aro, 365 U.S. at 341). 

This requirement existed before the 1952 Patent Act. 

Aro, 365 U.S. at 341 (“It is plain that § 271(c)—a part of 

the Patent Code enacted in 1952—made no change in the 

fundamental precept that there can be no contributory 

infringement in the absence of a direct infringement.”). 

Peerless and Solva implicitly—but necessarily—held that 

two parties’ performance of different steps of the claimed 

methods constituted direct infringement of those methods.

Certainly, some of the pre-1952 principles and cases 

cited above are more akin to what we today consider to be 

indirect infringement rather than direct infringement 

under § 271(a). But they all gave rise to liability and the 

1952 Patent Act codified all of them. In §§ 271(b) and (c),

it codified certain grounds for induced and contributory 

infringement. And in § 271(a), by using the plural term 

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“whoever,” it codified the common law rule that two 

parties who act in concert pursuant to a common plan or 

design to perform a claimed method are liable for joint 

infringement. 

Interpreting § 271(a) to allow for infringement by the 

concerted action of multiple parties is consistent with 

general common law principles of tort liability. The 

common law imposed joint liability when two or more 

parties acted in concert—alternatively referred to as 

concerted action or acting with another in pursuit of a 

common plan, design, or purpose—even without an agency relationship or contractual obligation. “One is subject 

to liability if he . . . does a tortious act in concert with 

[an]other pursuant to a common design with him.” Restatement (Second) of Torts § 876(a); see also 1 Edwin A. 

Jaggard, Hand-book of the Law of Torts § 67 (“[J]oint tort 

feasors are held responsible, not because of any relationship existing between them, but because of concerted 

action toward a common end. . . . All persons who aid, 

counsel, direct, or join in committing a tort are joint 

tortfeasors.”). Indeed, the common law imposed liability 

for harm resulting from multiple parties even if the 

individual acts of each party were not tortious. Prosser & 

Keeton on Torts § 52 (“A number of courts have held that 

acts which individually would be innocent may be tortious 

if they thus combine to cause damage.”); Fowler Vincent 

Harper, A Treatise on the Law of Torts § 302 (1933) 

(“Harper”) (“Joint liability in tort may be imposed in three 

types of situations: (1) where the actors concur in the 

performance of the tortious act or acts; (2) where, although there is no joint action, nevertheless the independent acts of several actors concur to produce harmful 

consequences; and (3) where by reason of some special 

relationship between the parties, joint liability is imposed.”). The agreement to act in concert can be express, 

implied, or a tacit understanding. Prosser & Keeton on 

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Torts § 46 (“Express agreement is not necessary, and all 

that is required is that there be a tacit understanding.”); 

Akamai, 692 F.3d at 1349 (Linn, J., dissenting) (agreement can be express or implied); Restatement (Second) of 

Torts § 876(a), cmt. a (“The agreement need not be expressed in words and may be implied and understood to 

exist from the conduct itself.”).

And while the post-1952 precedent is not a model of 

clarity on the circumstances in which concerted action or 

joint infringement creates liability under § 271(a), courts 

frequently recognized liability under § 271(a) in joint 

tortfeasor scenarios, not limited to vicarious liability. See, 

e.g., On Demand Mach. Corp. v. Ingram Indus., Inc., 442 

F.3d 1331, 1344–45 (Fed. Cir. 2006) (approving district 

court’s jury instruction that “[i]t is not necessary for the 

acts that constitute infringement to be performed by one 

person or entity. . . . Infringement of a patented process or 

method cannot be avoided by having another perform one 

step of the process or method. Where the infringement is 

the result of the participation and combined action(s) of 

one or more persons or entities, they are joint infringers 

and are jointly liable for the infringement.”); Hill v. Amazon.com, Inc., No. 2:02-cv-186, 2006 WL 151911, at *2

(E.D. Tex. Jan. 19, 2006) (“In the absence of an agency or 

contractual relationship, the case law appears to require a 

showing that the defendant and the third party are connected at least to the extent that the defendant must 

actually direct the third party to perform the remaining 

steps of the method.”); Shields v. Halliburton Co., 493 F. 

Supp. 1376, 1389 (W.D. La. 1980) (“Infringement of a 

patented process or method cannot be avoided by having 

another perform one step of the process or method.”), 

aff’d, 667 F.2d 1232 (5th Cir. 1982); see also Freedom 

Wireless Inc. v. Boston Commc’ns Grp., Inc., No. 06-1020, 

slip op. at 2–3 (Fed. Cir. Dec. 15, 2005) (noting district 

court’s finding direct infringement under § 271(a) on a 

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theory of joint infringement where two different companies acted in concert to perform all the method steps and 

instructing the jury: “if separate companies work together 

to perform all of the steps of a claim of a patent, the 

companies are jointly responsible, that is, responsible as a 

group for the infringement of the patent. Even if no 

single company performs all of the steps of a claim, the 

companies are jointly responsible.”); Applied Interact, 

LLC v. Vt. Teddy Bear Co., No. 04 Civ. 8713, 2005 WL 

2133416, at *4 (S.D.N.Y. Sept. 6, 2005) (adopting a “some 

connection,” not a vicarious liability, standard among 

joint infringers); Marley Mouldings Ltd. v. Mikron Indus., 

Inc., No. 02 C 2855, 2003 WL 1989640, at *3 (N.D. Ill. 

Apr. 30, 2003) (denying summary judgment of noninfringement where parties collectively performed all method steps and holding that “[a] party cannot avoid 

infringement merely by having another entity perform 

one or more of the required steps when that party is 

connected with the entity performing one or more of the 

required steps”); Cordis Corp. v. Medtronic AVE, Inc., 194 

F. Supp. 2d 323, 350 (D. Del. 2002), rev’d on other 

grounds, 339 F.3d 1352 (Fed. Cir. 2003) (finding sufficient 

evidence to support finding that there was “some connection” between two parties jointly performing method 

claim); Faroudja Labs., Inc. v. Dwin Elecs., Inc., No. 97-

20010, 1999 WL 111788, at *5 (N.D. Cal. Feb. 24, 1999) 

(recognizing that “a party [may be] liable for direct infringement of a process patent even where the various 

steps included in the patent are performed by distinct 

entities” if there is “some connection between the different 

entities”); Mobil Oil Corp. v. W.R. Grace & Co., 367 F. 

Supp. 207, 253 (D. Conn. 1973) (holding that Grace directly infringed despite the fact that its customers performed 

one of the claimed steps because “defendant, in effect, 

made each of its customers its agent in completing the 

infringement step knowing full well that the infringement 

step would in fact be promptly and fully completed by 

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those customers”); Metal Film Co. v. Metlon Corp., 316 F. 

Supp. 96, 110–11 (S.D.N.Y. 1970) (holding defendant 

could not avoid direct infringement by having an outside 

supplier perform one of the method steps). But see Mobil 

Oil Corp. v. Filtrol Corp., 501 F.2d 282, 291–92 (9th Cir. 

1974) (expressing doubt over the possibility of divided 

infringement liability). 

IV. Applying the Statutory Interpretation to this Case

Limelight is liable under § 271(a) for its actions and 

the actions of its customers in infringing the ’703 patent. 

First, Limelight is liable under the direction or control 

test, because Limelight has performed a number of steps

of the patented methods, and it has directed its customers 

to perform the remaining steps. Limelight is not an

innocent party who performed a single step. It is the 

mastermind of the infringement in this case. It performed all but one of the claim steps and it instructed, in 

fact it required, its customers to perform the other claim 

step before they could use Limelight’s content delivery 

system. Such a person, personally responsible for the 

performance of every claim step, has always been deemed 

an infringer under the law. In these circumstances, 

Limelight “uses” the patented method. Every time Limelight’s customers act, pursuant to its instruction to use its 

content delivery system, infringement is occurring. All of 

Akamai’s invention is used, all the claimed method steps 

are performed, and all the economic benefit of Akamai’s 

innovation is stolen. And Limelight is the one who profits 

from this infringement. Limelight is using Akamai’s 

patented invention and is responsible for the performance 

of every patented step. 

Limelight could also be held liable as a joint infringer, 

acting in concert with the customers pursuant to a common purpose, design, or plan. Limelight and its content 

provider customers share a common purpose, design, or 

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plan: to provide website information to Internet users. 

Limelight knowingly works together with its customers to 

achieve that result, jointly performing all the steps of the 

patented method and receiving exactly the economic 

benefit secured by the patent. Limelight’s service improves content delivery to Internet users, offering its 

customers faster, more efficient delivery of tagged content 

coupled with control and flexibility over untagged content. 

A jury has found that all of the steps of the claims at issue 

are performed by the collective actions of Limelight and 

its customers. And these steps are performed in concert

pursuant to contract. 

Limelight requires all of its customers who wish to 

use its service to sign a standard contract delineating the 

actions that customers must perform to use the Limelight 

service—actions that include steps of the patented method. The fact that Limelight did not tell its customers 

what website content to tag is irrelevant to infringement 

of the claims at issue, which do not discriminate among 

tagged content. It is true that the contract does not 

compel the customer to use Limelight’s service. But if the 

customer does choose to use Limelight’s service to deliver 

content, it must perform some of the claimed method 

steps, and thus acts in concert with Limelight. The fact 

that a customer may choose not to act in concert with 

Limelight does not insulate Limelight from liability when 

that customer actually chooses to do so. 

The Constitution and 35 U.S.C. § 154 grant patentees 

the right to exclude others from using the patented invention in the United States. Akamai was undoubtedly 

harmed—its entire patented process was used by others 

for commercial gain all in the United States. This harm 

is identical whether Limelight performed all the steps or 

collaborated with its customers to divide them up. Limelight benefitted from the infringing use by selling its 

services, which provided exactly the faster, more efficient 

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content delivery system invented by Akamai. Limelight

knowingly performed each step except the tagging step,

and it knew that its customers would perform that tagging step. Its content delivery system would not work 

unless the customer performed the tagging step. In fact, 

the contract it had with its customers required them to 

perform that tagging step if they used the Limelight 

service. Every step of the patented method was performed and Limelight and its content provider customer 

achieved exactly the economic benefit conferred by the 

patent without having to pay a royalty for its use. Under 

common law joint tortfeasor principles, Limelight’s conduct traditionally gave rise to liability. Under common 

law patent principles, this conduct traditionally gave rise 

to liability. For centuries, up until our recent decisions, 

Limelight would have been liable for patent infringement. 

And the majority makes no argument that Limelight 

should not be held liable. 

V. Responding to the Majority

The majority’s creation of a narrow patent-specific 

universe of joint infringement liability construes the 

Patent Act in ways that are both internally inconsistent 

and inconsistent with general tort principles.5 Section 

271(a) covers joint infringement, including situations 

which give rise to joint tortfeasor liability. It includes 

liability for a tortfeasor like Limelight who performed all 

the method steps but one and then directed its customers 

to perform the final step. The direction or control stand5 Interestingly, the majority’s joint enterprise 

standard is more akin to joint tortfeasor than agency. It 

is discussed as a form of “vicarious liability.” However, 

like other forms of joint tortfeasor liability and unlike 

agency or contract obligation, it creates joint and several 

liability among the participants of the joint enterprise. 

 

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ard was not limited to situations where there was vicarious liability at common law and there is no reason to read 

such a limitation into § 271(a). Similarly, the common 

law does not limit concerted action to instances where 

parties are acting in furtherance of an agency relationship, contractual obligation, or joint enterprise. See

Prosser & Keeton on Torts § 46; Restatement (Second) of 

Torts § 876; Harper § 302. 

The majority cites a number of treatises for the proposition that mere knowledge of another’s tortious activity is 

not enough to give rise to liability. I agree. Joint tortfeasor liability requires concerted action pursuant to a common plan, purpose, or design. Joint tortfeasors are both 

acting to create a single indivisible harm. I agree with 

the majority that just knowing that someone else is acting 

(when you yourself do nothing) does not subject you to

liability. 

And importantly, I am not importing a knowledge requirement into § 271(a) that would be incompatible with 

the strict liability nature of the tort of infringement. 

There is no knowledge of the patent requirement under 

§ 271(a) and neither my standard nor the majority’s 

imports one. Both standards, however, do require 

knowledge to attribute the acts of one party to another. 

The majority’s joint enterprise standard requires 

knowledge, in fact, an agreement between the parties and 

right of mutual control. Likewise, the joint tortfeasor 

standard requires knowledge. Neither requires 

knowledge of the patent or knowledge of the harm that 

will be caused. Rather, both adopt the common sense 

principle that a party cannot be held liable for the actions 

of another without knowing of that party’s actions and 

some form of agreement or direction or control. Here 

there is no dispute that Limelight itself acted (performed 

all but one of the method steps) and knew precisely the 

actions its customers would take and, in fact, it instructed 

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them as to how to take those actions. This undoubtedly 

comports with any knowledge requirement under joint 

tortfeasor law that would attribute to Limelight those 

acts taken by its customers. 

The majority criticizes the dissent for not incorporating into § 271(a) all joint tortfeasor scenarios. The answer 

is clear: not all joint tortfeasor scenarios are permissible 

under the language of § 271(a), and of course, the statute’s language controls. For example, it is true that at 

common law the action of encouraging another to commit 

a tort (traditional notions of inducement) makes you a 

joint tortfeasor. And because such inducement is directly 

and undisputedly covered by § 271(b), this common law 

joint tortfeasor does not escape liability under § 271. 

However, that particular joint tortfeasor scenario does not 

likewise create liability under § 271(a) because the language of § 271(a) precludes it. Section 271(a) in relevant 

part says “whoever . . . uses . . . any patented invention.” 

To be liable as a joint tortfeasor under § 271(a), all the 

elements or steps of the claim must be performed, and 

each accused joint tortfeasor must perform at least one of 

the steps pursuant to some common purpose, design or 

plan. If you perform none of the steps, you are not jointly 

using the patented invention, and thus are not a joint 

tortfeasor covered by § 271(a). 

Akamai, the patentee, is harmed identically whether 

Limelight performed all of the method steps or whether 

Limelight performed three and had its customer perform 

the fourth. Under the majority’s reading of the statute, 

the patentee has no redress for the harm if two people act 

together to perform the patented method but does have 

redress if that identical method is performed by a single 

entity. It is difficult for me to conceive of how that guarantees the patentee’s right of exclusivity or compensates 

the patentee when that right of exclusivity is clearly 

violated. The majority claims that the dissent would 

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extend liability to independent arms-length actors who 

just happen to collectively perform the claimed steps. Not 

so. Concerted action pursuant to a common plan, purpose, or design requires that “[p]arties are acting in 

concert when they act in accordance with an agreement to 

cooperate in a particular line of conduct or to accomplish a 

particular result.” Restatement (Second) of Torts § 876, 

cmt. a. Such concerted action has occurred in this case. 

Limelight performed all but one step of that patented 

method and its customers, pursuant to a contract for 

Limelight’s services, performed the final step (tagging). 

Limelight and those customers had an express agreement 

that when Limelight’s content delivery system was used, 

the customers would tag content and Limelight would 

perform all the other steps—this is “an agreement to 

cooperate in a particular line of conduct or to accomplish a 

particular result.” 

I have not “blithely tossed [common law principles of 

joint tortfeasor] aside.” Maj. at 23. The majority has 

created a straw man and in folly beat it down. But joint 

tortfeasor concerted action, according to a common plan, 

purpose, or design, is not that straw man. My interpretation of the Patent Act embraces the common law tort 

principles. There was liability for what Limelight did 

here prior to the 1952 Patent Act, and the Patent Act 

continues to give rise to liability for such infringement in 

§ 271(a). I do not agree with the majority that Congress 

intentionally sought to do away with such liability, and

the plain language of the statute does not comport with 

such claims. 

The majority’s complaints about predatory customer 

suits are a smokescreen. Maj. at 24. The only accused 

infringer in this case is Limelight. We do not, and need 

not, decide whether Limelight’s customers should be 

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liable, as none of those customers have been sued by 

Akamai.6 

The majority’s concern that joint tortfeasor liability 

will cause a “drastic expansion of predatory customer 

suits” is unwarranted. Maj. at 24. The majority’s dramatic rhetoric is meant to appeal to the frenzy over 

“trolls.” Concerns about customer suits stem from the fact 

that patentees might choose to sue less sophisticated 

customers who lack the resources or incentive to defend 

against the patent suit, while the manufacturers, who 

generally have a greater interest and ability to defend 

against the suit, cannot participate in the lawsuit. See, 

e.g., Microsoft Corp. v. DataTern, Inc., 755 F.3d 899, 904–

907 (Fed. Cir. 2014) (prohibiting Microsoft’s declaratory 

judgment action despite the fact that the patentee sued 

over 100 customers). 

These concerns do not exist in the joint tortfeasor context because if a customer were ever sued, the manufacturer can be joined voluntarily (or even involuntarily). 

Where it is the combined actions of the customer and 

manufacturer pursuant to a common plan that give rise to 

liability, if the customer is sued, the manufacturer can 

6 While not deciding whether Limelight’s customers 

could be liable, the Supreme Court has stated that “[t]he 

right to use is a comprehensive term and embraces within 

its meaning the right to put into service any given invention.” Bauer, 229 U.S. at 10–11. And we note that a 

system claim is infringed by an end-user when “the system is put into service,” regardless of whether the enduser possesses or made the system. Centillion Data Sys., 

LLC v. Qwest Commc’ns Int’l, Inc., 631 F.3d 1279, 1284–

85 (Fed. Cir. 2011); NTP, 418 F.3d at 1317. 

 

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join and defend against the suit.7 Once joined, the manufacturer could secure a judgment that would resolve suits 

as against all its customers. If the manufacturer secures 

a judgment against the patentee, the patentee could be 

collaterally estopped from bringing any other customer 

suits. If the patentee is successful against the manufacturer and recovers damages, it cannot separately recover 

damages from the customers who use that product. 

Glenayre Elecs., Inc. v. Jackson, 443 F.3d 851, 864 (Fed. 

Cir. 2006) (“[A] party is precluded from suing to collect 

damages for direct infringement by a buyer and user of a 

product when actual damages covering that very use have 

already been collected from the maker and seller of that 

product.”). The law is clear: if the patentee recovers 

damages from Limelight here, it cannot later recover 

damages from any customers of Limelight; there is no 

double dipping. 

Finally, to do either what the majority proposes or 

what I propose requires en banc action, as it is admittedly 

at odds with binding precedent. Despite mentioning the 

joint enterprise standard twelve times in the opinion and 

concluding that the collaborative actions of Limelight and 

its customers do not give rise to joint enterprise liability,8

7 And if a customer were found liable (such as 

Limelight’s content provider customers), that customer 

would only be jointly and severally liable for the single act 

of infringement that it performed in concert with Limelight. Only the manufacturer, Limelight, is liable for the 

harm caused by all of the uses of its software. 

8 It is troubling that the majority articulates a new 

standard for liability, joint enterprise, which is in conflict 

with our prior precedent and then decides this factual 

question on appeal, with no opportunity for briefing, 

argument, or record development by the parties. “Whether [the joint enterprise] elements exist is frequently a 

 

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32 AKAMAI TECHNOLOGIES, INC. v. LIMELIGHT NETWORKS, INC.

the Majority claims that it is not adopting joint enterprise 

liability. It is not, and cannot adopt the joint enterprise 

standard, because one panel cannot overrule a prior panel 

decision. Our opinion in Golden Hour Data Systems, Inc. 

v. emsCharts, Inc., 614 F.3d 1367, 1371, 1380–81 (Fed. 

Cir. 2010) found no liability where two defendants 

“formed a strategic partnership, enabled their two programs to work together, and collaborated to sell the two 

programs as a unit” that practiced all of the claimed 

method steps. The jury had found infringement under the 

direction or control test in Golden Hour, our court held 

that those circumstances, the very same ones that would 

qualify for joint enterprise, do not give rise to liability. Id.

at 1381. And Judge Linn’s dissent in Akamai, which was 

joined by Judge Prost, correctly explained: “Because the 

parties in [Golden Hour] would have satisfied the test for 

joint enterprise based on common purpose and an equal 

right of mutual control, . . . the en banc court should 

expressly overrule the holding in that case.” Akamai, 692 

F.3d at 1349 (Linn, J., dissenting). 

* * * * *

Congress codified existing common law joint tortfeasor principles in §§ 271(a), (b), and (c). Section 271(a) 

covers direct infringement, which occurs when all the 

steps of the method are performed either by a single 

entity or multiple entities acting in concert or collaboration, jointly, or under direction or control. This does not 

extend to arms-length actors who unwittingly perform a 

single step—there must be concerted action to achieve a 

common goal. The plain language of § 271(a), and in 

particular Congress’ decision to make liable “whoever . . . 

uses . . . any patented invention,” expressly includes joint 

question of fact for the jury.” Restatement (Second) of 

Torts § 491, cmt. c. 

 

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AKAMAI TECHNOLOGIES, INC. v. LIMELIGHT NETWORKS, INC. 33

tortfeasor concerted action. To conclude otherwise renders the statute’s use of the word “whoever” internally 

inconsistent. There is no question that §§ 101, 161, and 

171, which state “whoever invents,” includes the concerted action of multiple inventors each playing a part in the 

conception of the patented invention. Likewise “whoever 

uses” includes the concerted action of multiple parties 

each playing a part in using the patented process. The 

majority’s single entity rule is judicial fiction which 

upsets the settled expectations of the inventing and 

business community. I respectfully dissent from the 

majority’s construction which is inconsistent with the 

plain language of the statute, renders the statute internally inconsistent, and creates a gaping hole in infringement which no one even attempts to justify. 

Case: 09-1372 Document: 316-2 Page: 62 Filed: 05/13/2015