FOR PUBLICATION

UNITED STATES COURT OF APPEALS

FOR THE NINTH CIRCUIT

UNITED STATES OF AMERICA,

Plaintiff-Appellee,

v.

CARSTEN IGOR ROSENOW, AKA 

Carlos Senta,

Defendant-Appellant.

No. 20-50052

D.C. No.

3:17-cr-03430-

WQH-1

OPINION

Appeal from the United States District Court

for the Southern District of California

William Q. Hayes, District Judge, Presiding

Argued and Submitted June 8, 2021

Pasadena, California

Filed April 27, 2022

Before: Susan P. Graber, Consuelo M. Callahan, and 

Danielle J. Forrest, Circuit Judges.

Opinion by Judge Forrest;

Dissent by Judge Graber
2 UNITED STATES V. ROSENOW

SUMMARY*

Criminal Law

The panel affirmed a conviction and sentence on one 

count of attempted sexual exploitation of a child, 18 U.S.C. 

§ 2251(c), and one count of possession of sexually explicit 

images of children, 18 U.S.C. § 2252(a)(4)(B), in a case in 

which the defendant was arrested returning from the 

Philippines, where he engaged in sex tourism involving 

minors.

The defendant arranged these illegal activities through 

online messaging services provided by electronic service 

providers (ESPs) Yahoo and Facebook. His participation in 

foreign child sex tourism was initially discovered after 

Yahoo investigated numerous user accounts that Yahoo 

suspected were involved in child exploitation. 

The defendant argued that the evidence seized from his 

electrical devices upon his arrest should have been 

suppressed because Yahoo and Facebook were acting as 

government agents when they searched his online accounts. 

The panel rejected the defendant’s arguments (1) that two 

federal statutes—the Stored Communications Act and the 

Protect Our Children Act—transformed the ESPs’ searches 

into governmental action, and (2) that the government was 

sufficiently involved in the ESPs’ searches of the 

defendant’s accounts to trigger Fourth Amendment 

protection. 

* This summary constitutes no part of the opinion of the court. It 

has been prepared by court staff for the convenience of the reader.
UNITED STATES V. ROSENOW 3

The defendant argued that he had a right to privacy in his 

digital data and that the government’s preservation requests 

and subpoenas, submitted without a warrant, violated the 

Fourth Amendment. The panel disagreed. The panel held 

(1) the government’s requests pursuant to 18 U.S.C. 

§ 2703(f) that Yahoo preserve records related to the 

defendant’s private communications did not amount to an 

unreasonable seizure; and (2) the defendant did not have a 

legitimate expectation of privacy in the limited digital data 

sought in the government’s subpoenas, where the subpoenas 

did not request any communication content from the 

defendant’s accounts and the government did not receive any 

such content in response to the subpoenas.

The defendant argued that the government’s search 

warrant affidavit failed to establish probable cause because 

it did not include any images of child pornography or any 

reasonable factual descriptions of such images. Rejecting 

this argument, the panel concluded that the affidavit—which 

described Yahoo’s internal investigation and the resulting 

findings, as well as the information Facebook provided to 

the National Center for Missing and Exploited Children after 

searching the defendant’s accounts—established a fair 

probability that child pornography would be found on the 

defendant’s electronic devices. 

The defendant argued that the jury was not properly 

instructed on the § 2251(c) count—attempted sexual 

exploitation of a child—because the instruction did not state 

that the “purpose” element of § 2251(c) was satisfied only if 

the government proved that he would not have acted but for

his desire to produce a visual depiction of the sexuallyexplicit conduct. The panel saw no basis to conclude that 

“purpose,” as used in § 2251(c), has a causal or results 

requirement.
4 UNITED STATES V. ROSENOW

The defendant, who was convicted of a single count of 

possession of child pornography involving the exploitation

of several child victims, argued that the district court 

improperly sentenced him as if he had been convicted on 

multiple possession counts. The district court increased his 

base offense level pursuant to the Sentencing Guidelines’ 

multiple-count instruction set forth in U.S.S.G. 

§§ 2G2.1(d)(1), 2G2.2(c)(1), which applies where more than 

one minor is exploited in an offense in which the defendant 

caused a minor to engage in sexually explicit conduct for the 

purpose of producing child pornography. Distinguishing 

United States v. Chilaca, 909 F.3d 289 (9th Cir. 2018), the 

panel wrote that there was no impermissible double counting 

here, as the enhancements were premised on separate 

exploitative acts.

Judge Graber dissented only as to the question whether, 

in conducting its searches of the defendant’s chat messages, 

Yahoo was acting as an instrument or agent of the 

government. Judge Graber applied the two-part test set forth 

in United States v. Young, 153 F.3d 1079 (9th Cir. 1998) (per 

curiam). As to the first prong, she wrote that the government 

knew of and acquiesced in Yahoo’s intrusive conduct, and 

she rejected the suggestion that this prong would be met only 

if Yahoo’s conduct had been illegal. As to the second prong, 

she wrote that Yahoo’s motivation to conduct the searches 

was intertwined with, and dependent on, the government’s 

enforcement of criminal laws.
UNITED STATES V. ROSENOW 5

COUNSEL

Timothy A. Scott (argued), Nicolas O. Jimenez, and Marcus 

Bourassa, Singleton Schreiber McKenzie & Scott, San 

Diego, California, for Defendant-Appellant.

Mark R. Rehe (argued), Assistant United States Attorney; 

Daniel E. Zipp, Chief, Appellate Section, Criminal Division;

Randy S. Grossman, Acting United States Attorney; United 

States Attorney’s Office, San Diego, California; for 

Plaintiff-Appellee.

Gregory L. Doll and Jamie O. Kendall, Doll Amir & Eley

LLP, Los Angeles, California, for Amicus Curiae Oath 

Holdings Inc.

OPINION

FORREST, Circuit Judge:

Defendant Carsten Rosenow was arrested returning from 

the Philippines, where he engaged in sex tourism involving 

minors. Rosenow arranged these illegal activities through 

online messaging services provided by Yahoo and 

Facebook, and his participation in foreign child sex tourism 

was initially discovered after Yahoo investigated numerous 

user accounts that Yahoo suspected were involved in child 

sexual exploitation. Following a jury trial, Rosenow was 

convicted on one count of attempted sexual exploitation of a 

child, 18 U.S.C. § 2251(c), and one count of possession of 

sexually explicit images of children, 18 U.S.C. 

§ 2252(a)(4)(B).
6 UNITED STATES V. ROSENOW

On appeal, Rosenow argues that the evidence seized 

from his electronic devices upon his arrest should have been 

suppressed because, among other reasons, Yahoo and 

Facebook (which also searched his accounts on its platform) 

were government actors when they investigated his accounts 

without a warrant and reported the evidence of child sexual 

exploitation that they found to the National Center for 

Missing and Exploited Children (NCMEC), in supposed 

violation of Rosenow’s Fourth Amendment rights. He 

further argues that the district court improperly instructed the 

jury on the required mental state for his sexual exploitation 

charge and miscalculated the sentence on his possession 

charge. We have jurisdiction under 28 U.S.C. § 1291, and 

we affirm Rosenow’s conviction and sentence.

I. BACKGROUND

A. Electronic Communication Services and Mandatory 

Reporting

Yahoo and Facebook are electronic communication 

service providers (ESPs) that provide online private 

messaging services. These services allow users to share 

instant messages, images, and videos that only the sender 

and recipient can see. Both companies have policies 

governing user privacy.

Yahoo’s privacy policy during the relevant period stated 

that Yahoo “stores all communications content” and reserves 

the right to share that information “to investigate, prevent, or 

take action regarding illegal activities . . . , violations of 

Yahoo’s terms of use, or as otherwise required by law.”

Yahoo’s internal practice was to terminate or suspend user 

accounts that contained child pornography images or videos, 

but communication about child pornography 

unaccompanied by offending images did not trigger these 
UNITED STATES V. ROSENOW 7

actions. During the events of this case, Yahoo Messenger, 

the specific service that Rosenow used, did not transmit 

“photographs or videos or other files shared between two 

users” over Yahoo’s servers, so Yahoo did not store them.

Facebook’s privacy policy likewise stated that it has the 

right to “access, preserve and share information when [it] 

ha[s] a good faith belief it is necessary to: detect, prevent and 

address fraud and other illegal activity.” And it was 

Facebook’s internal policy to search users’ accounts anytime 

it received legal process indicating a “child safety” concern 

or suggesting that child exploitation materials might exist on 

its platform. If Facebook found content violating its terms of 

use, including child pornography, it performed a more 

extensive investigation and took “appropriate action . . .

including removing the offending content or disabling the 

account.”

The Protect Our Children Act of 2008 requires ESPs to 

report “any facts or circumstances from which there is an 

apparent violation of” specified criminal offenses involving 

child pornography. 18 U.S.C. § 2258A(a)(1)–(2). ESPs 

report to the NCMEC, a non-profit organization that is 

statutorily required to operate the “CyberTipline,” which is 

an online tool that gives ESPs “an effective means of 

reporting internet-related child sexual exploitation.”

34 U.S.C. § 11293; see 18 U.S.C. § 2258A(a)(1). NCMEC 

is required to make every “CyberTip” it receives available to 

federal law enforcement. 18 U.S.C. § 2258A(c)(1). ESPs 

that fail to report “apparent violation[s]” of the specified 

criminal statutes involving child pornography face 

substantial fines. Id. § 2258A(a)(1), (e).
8 UNITED STATES V. ROSENOW

B. Yahoo’s Investigation and CyberTips

In September 2014, an online international money 

transfer company filed CyberTips and told Yahoo about ten 

Yahoo users who were selling child pornography produced 

in the Philippines. Yahoo connected those accounts to over 

a hundred other Yahoo user accounts selling child 

pornography and live-streaming sex acts with children in the 

Philippines. The following month, Yahoo filed a 

supplemental CyberTip report with the NCMEC and notified 

the FBI and Homeland Security Investigations (Homeland 

Security) about its report. Yahoo took the additional step of 

contacting law enforcement because it had determined “that 

there were children that were being actively exploited, and 

there were some users that seemed to be engaged in 

travelling to abused children or other types of activity like 

this that had some exigency” and Yahoo “wanted to be sure 

that law enforcement was aware that there were these 

children in danger and would be able to prioritize [Yahoo’s] 

report over the other thousands of reports that [the 

government] might have received during that time period.”

That same month, Yahoo also met with the FBI and 

Homeland Security at the NCMEC to discuss Yahoo’s 

internal investigation. Yahoo disclosed additional 

information regarding its suspicious users’ accounts. The 

FBI’s Major Case Coordination Unit (MCCU) subsequently 

opened its own investigation, “Operation Swift Traveler,” to 

investigate Yahoo’s evidence.

Yahoo remained suspicious that there were additional 

users involved in the criminal scheme it was uncovering.

Continuing its own internal investigations, Yahoo later 

identified several hundred additional users who were selling 

or buying child-exploitation content from the Philippines. 

Rosenow was one of the users identified in these efforts. 
UNITED STATES V. ROSENOW 9

Yahoo determined that Rosenow was a buyer who regularly 

communicated with sellers about his child sex tourism in the 

Philippines. In December 2014, Yahoo filed another 

CyberTip and arranged a second meeting with federal 

authorities to discuss its continued internal investigation. In 

December 2014 (and March 2015, and June 2015), the FBI 

requested that Yahoo preserve the communications of its 

users (including Rosenow) who were associated with 

Operation Swift Traveler.1

After filing its December 2014 CyberTip, Yahoo learned 

that Homeland Security had arrested a prolific buyer of child 

pornography through Operation Swift Traveler and did not 

intend to conduct any further investigations. Concerned that 

“a rather large portion of the Philippine webcam and sex 

trafficking activity” had been missed, Yahoo conducted 

further internal investigations of the arrested buyer’s texts 

with sellers in the Philippines, and consequently discovered 

more conversations between the sellers and Rosenow. In 

these conversations, Rosenow repeatedly asked for pictures 

of children whom he was arranging to meet for sex in the 

Philippines. In some communications, he requested, and 

appears to have received, lewd pictures from an adolescent 

Filipina girl. Yahoo filed a CyberTip in December 2015 

based on its additional information about Rosenow and other 

users, and it met with the FBI at the NCMEC again in 

February 2016 to discuss its recent internal investigations.

1 Under the Stored Communications Act, an ESP, upon receiving a 

preservation request, “shall take all necessary steps to preserve records 

and other evidence in its possession” for up to 180 days “pending the 

issuance of a court order or other process.” 18 U.S.C. § 2703(f).
10 UNITED STATES V. ROSENOW

C. FBI Agent Cashman’s Investigation and Facebook’s 

CyberTips

In early 2015, the FBI’s MCCU sent a lead about 

Rosenow to Agent Colleen Cashman in the FBI’s San Diego 

office. Between March 2015 and January 2017, Agent 

Cashman received Yahoo’s initial CyberTips, but she did not 

receive the December 2015 CyberTip. At some point before 

January 2017, the FBI applied for a search warrant for 

Rosenow’s Yahoo account, but the U.S. Attorney’s Office 

stated that the basis for probable cause from Yahoo’s earlier 

CyberTips “had become dated or stale.”

In January 2017, the MCCU sent Agent Cashman 

Yahoo’s December 2015 CyberTip, which renewed her 

investigation. Agent Cashman learned that Rosenow had a 

Facebook account under a different name, and she sent 

preservation requests to Facebook in January and May 2017 

through its Law Enforcement Online Request System 

(LEORS). In March and June 2017, she filed administrative 

subpoenas through LEORS for Rosenow’s “[b]asic 

subscriber information and IP log-in information” for both 

of his user accounts and indicated that the case involved 

“child safety.” Because Facebook automatically reviewed 

user accounts whenever a LEORS request indicated a “child 

safety” concern or suggested that child exploitation 

materials might exist, Agent Cashman’s subpoenas triggered 

Facebook’s review of Rosenow’s account activity, including 

his “messages, timelines, photos, IP addresses, and machine 

cookies.” Facebook discovered child-exploitation content 

that violated its terms of use, immediately disabled 

Rosenow’s accounts, and filed two CyberTips with 

NCMEC.

NCMEC promptly forwarded Facebook’s CyberTips to 

Agent Cashman. The CyberTips showed that Rosenow had 
UNITED STATES V. ROSENOW 11

sent three files that Facebook classified as “child 

pornography” and provided excerpts from Rosenow’s 

conversations negotiating sex acts with three underage girls 

in the Philippines. He told one girl that he wanted to video 

their encounter, and he told another that he loved the nude 

pictures he had taken of her during a previous encounter. 

When Agent Cashman submitted her initial subpoena in 

March 2017, she did not know that it would trigger 

Facebook’s automatic internal searches. But she 

acknowledges that, because she submitted this subpoena, she 

received information from NCMEC about Rosenow’s 

Facebook account that she could not otherwise have 

obtained without a warrant.2

In July 2017, Agent Cashman prepared affidavits 

seeking search warrants for Rosenow’s person, baggage, and 

home, relying almost exclusively on evidence in Yahoo’s 

and Facebook’s CyberTips. The warrants sought evidence of 

child pornography offenses and child sex tourism. Two days 

later, with a search warrant in hand, the FBI arrested 

Rosenow when he returned from a trip to the Philippines. 

The FBI’s searches of Rosenow’s electronic devices 

revealed significant child pornography, including numerous 

videos of Rosenow himself performing sex acts on 

prepubescent Filipina girls ranging from approximately 10 

to 15 years old.

2 Agent Cashman’s second subpoena issued to Facebook in June 

2017 related to a different user account that Rosenow did not use for his 

illicit activities. This subpoena did not lead Facebook to file any 

additional CyberTips.
12 UNITED STATES V. ROSENOW

D. District Court Proceedings

Rosenow was indicted for attempted sexual exploitation 

of a child, 18 U.S.C. § 2251(c), possession of sexually 

explicit images of children, 18 U.S.C. § 2252(a)(4)(B), and 

travel with intent to engage in illicit sexual conduct, 

18 U.S.C. § 2423(b). Rosenow moved to suppress all the 

evidence obtained from Yahoo’s and Facebook’s searches of 

his private online communications, arguing that the 

companies “searched at the government’s behest” and, 

therefore, their conduct was government action that violated 

the Fourth Amendment’s warrant requirement. Additionally, 

Rosenow claimed that the government’s preservation orders 

and subpoenas were unlawful warrantless seizures under 

Carpenter v. United States, 138 S. Ct. 2206 (2018), and that 

the warrant used to search and seize his property was based 

on information obtained in illegal searches and lacked 

probable cause.

After a two-day evidentiary hearing, the district court 

denied his motions. The court concluded that Yahoo and 

Facebook both acted independently in investigating 

Rosenow “pursuant to legitimate business purposes” of 

excluding users involved in child abuse and exploitation and 

that the companies’ compliance with the mandatory 

reporting statute did not convert them into government 

actors. As to the preservation orders, the court found no 

Fourth Amendment violation because they “did not interfere 

with [Rosenow]’s use of his accounts and did not entitle the 

[g]overnment to obtain any information without further legal 

process.” The court similarly found no Fourth Amendment 

violation for the administrative subpoenas, concluding that, 

“[u]nlike the location information in Carpenter,” Rosenow 

“had no reasonable expectation of privacy in the subscriber 

information and the IP log-in information [he] voluntarily 
UNITED STATES V. ROSENOW 13

provided to [Facebook] in order to establish and maintain his 

account.” Finally, the court concluded that the facts set forth 

in the search warrant affidavit were sufficient to support 

probable cause that evidence of child pornography offenses 

would be found, and Rosenow failed to identify any 

misrepresentations or material omissions to overcome this 

finding.

In August 2019, Rosenow’s jury trial commenced on the 

charges of attempted sexual exploitation of a child and 

possession of sexually explicit images of children. Rosenow 

stipulated that he knowingly possessed five depictions of 

child pornography, including two video recordings of 

himself engaging in sexually explicitly conduct with minor 

girls. For the attempted exploitation charge, Rosenow 

requested a jury instruction stating that the “purpose” mental 

state element required for conviction was satisfied only if the 

government proved that he “would not have acted but for his 

desire to produce a visual depiction of the sexually-explicit 

conduct.” The district court rejected his proposed instruction 

and instead instructed the jury that the government had to 

prove that “producing a visual depiction of a minor engaged 

in sexually explicit conduct” was Rosenow’s “dominant, 

significant or motivating” purpose, not that it was his “sole 

purpose.” The jury convicted Rosenow on both charges.

At sentencing, Rosenow objected to his Presentence 

Report’s sentencing calculation as multiplicitous, arguing 

that he was convicted of only one count of possession but 

would be punished as if he had been convicted of four 

separate counts, in violation of United States v. Chilaca, 

909 F.3d 289 (9th Cir. 2018), and the Sixth Amendment. The 

district court overruled Rosenow’s objection and held that 

the multiple-count calculations were proper. Rosenow was 
14 UNITED STATES V. ROSENOW

sentenced to 300 months’ imprisonment and lifetime 

supervised release.

II. DISCUSSION

In reviewing a denial of a motion to suppress, we review 

the district court’s factual findings for clear error and its 

legal conclusions de novo. United States v. Vandergroen, 

964 F.3d 876, 879 (9th Cir. 2020), cert. denied, 141 S. Ct. 

1696 (2021). We also review de novo “whether a jury 

instruction misstates the law,” United States v. Rodriguez, 

971 F.3d 1005, 1012 (9th Cir. 2020), and whether the district 

court correctly interpreted and applied the Sentencing 

Guidelines, United States v. Martinez-Rodriguez, 472 F.3d 

1087, 1094 (9th Cir. 2007).

A. Search and Seizure Issues

1. Were the ESPs an “instrument or agent” of the 

government?

The Fourth Amendment guarantees the right to be free 

from “unreasonable searches and seizures.” U.S. Const. 

amend. IV. The Fourth Amendment regulates only 

governmental action; it does not protect against intrusive 

conduct by private individuals acting in a private capacity. 

United States v. Jacobsen, 466 U.S. 109, 113 (1984). The 

Constitution does, however, “constrain[] governmental 

action by whatever instruments or in whatever modes that 

action may be taken.” Lebron v. Nat’l R.R. Passenger Corp., 

513 U.S. 374, 392 (1995) (internal quotation marks and 

citation omitted). Thus, a private search or seizure may 

implicate the Fourth Amendment where the private party 

acts “as an agent of the Government or with the participation 

or knowledge of any governmental official.” Jacobsen, 
UNITED STATES V. ROSENOW 15

466 U.S. at 113 (internal quotation marks and citation 

omitted).

“A defendant challenging a search conducted by a 

private party bears the burden of showing the search was 

governmental action.” United States v. Young, 153 F.3d 

1079, 1080 (9th Cir. 1998) (per curiam). “Whether a private 

party should be deemed an agent or instrument of the 

Government for Fourth Amendment purposes necessarily

turns on the degree of the Government’s participation in the 

private party’s activities, a question that can only be resolved 

in light of all the circumstances.” Skinner v. Ry. Lab. Execs.’

Ass’n, 489 U.S. 602, 614–15 (1989) (internal quotation 

marks and citations omitted).

Rosenow argues that the evidence discovered by Yahoo 

and Facebook was obtained illegally and should be 

suppressed because they were acting as government agents 

when they searched his online accounts. His argument is 

two-fold: (1) two federal statutes—the Stored 

Communications Act and the Protect Our Children Act—

transformed the ESPs’ searches into governmental action, 

and (2) the government was sufficiently involved in the 

ESPs’ searches that they constituted governmental conduct. 

Each argument fails.

a. Does federal law transform the ESPs’ private 

searches into governmental action?

A federal regulatory scheme that authorizes and 

encourages private searches may transform a private search 

into governmental conduct. Id. at 614–16. Skinner 

considered a facial challenge to the Federal Railroad 

Administration’s regulations governing employee drug 

testing by private railroads. Id. The regulations mandated 

drug testing following a “major train accident,” but also 
16 UNITED STATES V. ROSENOW

permitted railroads to drug-test employees in other specified 

circumstances. Id. at 609–11. The Supreme Court held that 

the regulations—even those that did not mandate drug 

testing—implicated the Fourth Amendment because they 

amounted to governmental “encouragement, endorsement, 

and participation” in an otherwise private search. Id. at 615–

16. The Court emphasized that the regulations authorized 

private railroad companies to perform drug tests, preempted 

conflicting state laws and collective-bargaining terms, 

prohibited the railroad companies from contracting away 

their right to require the tests, required the companies to 

report certain evidence derived from the tests, and prohibited 

private employees from refusing to comply with the tests. Id. 

at 615–16. Thus, by removing “all legal barriers to the 

testing” and making “plain not only its strong preference for 

testing, but also its desire to share the fruits of such 

intrusions,” the Court held that the Federal Railroad 

Administration had transformed private searches by private 

companies into governmental action. Id. at 615–16.

Rosenow argues that, like the regulations in Skinner, 

federal regulation of ESP searches and disclosures trigger 

Fourth Amendment scrutiny because, taken together, the 

Stored Communications Act authorizes ESPs to conduct 

warrantless searches, see 18 U.S.C. § 2701(c), and the 

Protect Our Children Act requires private parties to report 

evidence derived from those searches to a government agent 

or entity, see id. § 2258A.3 As explained below, Rosenow’s 

argument is unconvincing.

3 The district court did not address Rosenow’s claim that the 

NCMEC is a governmental agent or entity for Fourth Amendment 

purposes. There is good reason to think that the NCMEC is, on the face 

of its authorizing statutes, a governmental entity under Fourth 
UNITED STATES V. ROSENOW 17

The Stored Communications Act criminalizes 

unauthorized searches of stored electronic communications 

content, 18 U.S.C. § 2701(a)–(b), but expressly excepts 

ESPs from liability. Id. § 2701(c)(1). This exception makes 

sense; otherwise, ESPs would be unable to ensure that user 

content does not violate the ESPs’ own terms of use. But 

unlike the regulations at issue in Skinner, which explicitly 

authorized railroads to administer drug and alcohol tests to 

their employees based on “reasonable suspicion,” Skinner, 

489 U.S. at 611, the Stored Communications Act does not 

authorize ESPs to do anything more than access information 

already contained on their servers as dictated by their terms 

of service. See 18 U.S.C. § 2701(c); Orin Kerr, A User’s 

Guide to the Stored Communications Act, and a Legislator’s 

Guide to Amending It, 72 Geo. Wash. L. Rev. 1208, 1212 

(2004) (“[E]ven if the Fourth Amendment protects files 

stored with an [E]SP, the [E]SP can search through all of the 

stored files on its server and disclose them to the government 

without violating the Fourth Amendment.”).

Additionally, the Protect Our Children Act disclaims any 

governmental mandate to search: § 2258A(f) provides that 

this statute “shall [not] be construed to require” an ESP to 

“monitor” users or their content or “affirmatively search, 

screen, or scan for” evidence of criminal activity. 18 U.S.C. 

§ 2258A(f). Mandated reporting is different than mandated 

searching. Our caselaw is clear that a private actor does not 

become a government agent simply by complying with a 

Amendment doctrine. See United States v. Ackerman, 831 F.3d 1292, 

1296 (10th Cir. 2016) (“NCMEC’s law enforcement powers extend well 

beyond those enjoyed by private citizens—and in this way it seems to 

mark it as a fair candidate for a governmental entity.”). For purposes of 

this case, we assume, without deciding, that the NCMEC is a 

governmental actor.
18 UNITED STATES V. ROSENOW

mandatory reporting statute. See Mueller v. Auker, 700 F.3d 

1180, 1191–92 (9th Cir. 2012) (“[Hospital] did not become 

a state actor simply because it complied with state law 

requiring its personnel to report possible child neglect to 

Child Protective Services.”); cf. Ferguson v. City of 

Charleston, 532 U.S. 67, 81 (2001) (holding that disclosure 

by medical professionals of “information that under rules of 

law or ethics is subject to reporting requirements” does not 

ordinarily violate the Fourth Amendment). Under both the 

Stored Communications Act and the Protect Our Children 

Act, Yahoo and Facebook are free to choose not to search

their users’ data. Therefore, when they do search, they do so 

of their own volition.

Moreover, unlike the regulations in Skinner, which 

prohibited railroad companies from contracting away their 

right to require drug tests, 489 U.S. at 615–16, neither statute 

at issue here prevents an ESP from contracting away its right 

to search users’ communications. See United States v. 

Stevenson, 727 F.3d 826, 830 (8th Cir. 2013). Thus, the 

statutes do not have the “clear indices of the Government’s 

encouragement, endorsement, and participation” sufficient 

to implicate the Fourth Amendment. Skinner, 489 U.S. 

at 615–16.

As a final note, persuasive authority also militates 

against Rosenow’s argument: three of our sister circuits have 

explicitly rejected the analogy of 18 U.S.C. § 2258A to the 

railroad regulations at issue in Skinner. See United States v. 

Miller, 982 F.3d 412, 424 (6th Cir. 2020), cert. denied, 

141 S. Ct. 2797 (2021); United States v. Ringland, 966 F.3d 

731, 736 (8th Cir. 2020), cert. denied, 141 S. Ct. 2797 

(2021); Stevenson, 727 F.3d at 830; United States v. 

Richardson, 607 F.3d 357, 364–67 (4th Cir. 2010); cf.

United States v. Meals, 21 F.4th 903, 907 (5th Cir. 2021) 
UNITED STATES V. ROSENOW 19

(rejecting defendant’s argument that § 2258A transformed 

Facebook into a government agent); United States v. 

Cameron, 699 F.3d 621, 636–38 (1st Cir. 2012) (holding that 

Yahoo’s statutory duty under federal law to report to 

NCMEC “did not impose any obligation to search for child 

pornography,” but “merely an obligation to report child 

pornography of which Yahoo[] became aware.”).

Those courts compared the railroad regulations only to 

§ 2258A of the Protect Our Children Act, and Rosenow 

points both to this statute and to the Stored Communications 

Act.4 But as explained, the Stored Communications Act does 

not mandate, encourage, or endorse private searches, and the 

reasoning of our sister circuits reinforces our conclusion that 

an ESP’s search of its users’ communications does not result 

inevitably from governmental encouragement as opposed to 

“private initiative.” Skinner, 489 U.S. at 615.

We hold that federal law did not transform Yahoo’s and 

Facebook’s private searches into governmental action.

b. Was there sufficient government involvement in 

the ESPs’ searches to implicate the Fourth 

Amendment?

Even if federal law does not render searches performed 

by private actors to be government conduct, a private search 

still may implicate the Fourth Amendment if there is a 

“sufficiently close nexus” between the government and the 

private entity’s challenged conduct. See Jackson v. Metro.

4 Rosenow argues for the first time in reply that § 230 of the 

Communications Decency Act also encourages ESPs to locate and 

disclose criminal activity to the government. We decline to consider this 

new argument. See CTIA-The Wireless Ass’n v. City of Berkeley, 

928 F.3d 832, 850 (9th Cir. 2019).
20 UNITED STATES V. ROSENOW

Edison Co., 419 U.S. 345, 351 (1974). In assessing whether 

a sufficient nexus exists, “the relevant inquiry is: (1) whether 

the government knew of and acquiesced in the intrusive 

conduct; and (2) whether the party performing the search 

intended to assist law enforcement efforts or further his own 

ends.” See United States v. Cleaveland, 38 F.3d 1092, 1094 

(9th Cir. 1994) (internal quotation marks and citation 

omitted).

i. Government knowledge and acquiescence

To satisfy the first requirement, the government must be 

involved in the search “either directly as a participant or 

indirectly as an encourager of the private citizen’s actions.”

United States v. Walther, 652 F.2d 788, 791 (9th Cir. 1981). 

The government’s knowledge of a private search, by itself, 

does not turn that search into one protected by the Fourth 

Amendment—were that not the case, the Fourth 

Amendment’s protections would cover a significant amount 

of private conduct of which the government was simply 

aware. Likewise, “[m]ere governmental authorization of a 

particular type of private search in the absence of more 

active participation or encouragement” does not trigger 

Fourth Amendment protection. Id. at 792; see also Flagg 

Bros., Inc. v. Brooks, 436 U.S. 149, 164 (1978) (“[M]ere 

acquiescence in a private action” does not transform a 

private actor into a government agent); Cameron, 699 F.3d 

at 637 (“We will not find that a private party has acted as an 

agent of the government simply because the government has 

a stake in the outcome of a search.” (internal quotation marks 

and citation omitted)). Nor do “de minimis or incidental 

contacts” between the government and a private entity. 

Walther, 652 F.2d at 791.

Here, the FBI knew about Yahoo’s ongoing internal 

investigations into the use of its platform for sexual 
UNITED STATES V. ROSENOW 21

exploitation of children in the Philippines, but, as the district 

court found, there is no evidence that “law enforcement was 

involved in or participated” in Yahoo’s investigations or that 

“law enforcement sought or received any assistance from 

Yahoo’s personnel in conducting its investigation outside of 

legal process.” Yahoo’s conduct was permissible, and it did 

not need approval from law enforcement to search 

Rosenow’s account and share any content it found that 

evidenced criminal activity. Yahoo had a contractual right 

under the terms of its privacy policy, to which Rosenow 

necessarily agreed, “to investigate, prevent, or take action 

regarding illegal activities” or “violations of Yahoo’s terms 

of use.” See Cleaveland, 38 F.3d at 1093–94 (finding 

insufficient governmental action because the private entity 

had the authority to search customer property under a 

customer service agreement); United States v. Miller, 

688 F.2d 652, 657 (9th Cir. 1982).

Nor was this a situation in which Yahoo was spurred into 

investigating Rosenow by the government or in which the 

government incentivized, directed, or encouraged Yahoo to 

continue its investigatory efforts after Yahoo initially 

informed law enforcement about its concerns related to some 

of its users. Quite the opposite. The record shows that Yahoo 

initiated its investigation due to information that it received 

from another private company. And it continued in its efforts 

primarily, if not entirely, because it was concerned that the 

government might drop the ball and not take sufficient action 

to address the ongoing sexual exploitation of children that 

Yahoo had uncovered.

For its part, Facebook was not independently proactive 

in searching Rosenow’s accounts in the same way that 

Yahoo was, but it nonetheless acted volitionally when it 

conducted its searches. As the district court found, the FBI 
22 UNITED STATES V. ROSENOW

issued a preservation request stating that it had “child safety”

concerns related to Rosenow’s account, but it “did not 

request that Facebook conduct any search or initiate any 

internal investigation into Rosenow’s accounts.” Rather, 

Facebook’s internal policies required it to review Rosenow’s 

accounts for inappropriate material because Facebook had 

received notice from law enforcement that conduct 

threatening child safety could be occurring in Rosenow’s 

accounts. The government’s preservation request triggered 

Facebook’s internal investigation policy, but Facebook 

independently chose to search Rosenow’s accounts and take 

corrective action after discovering content that violated its 

terms of use. Accordingly, we conclude that the 

government’s involvement with Yahoo’s and Facebook’s 

internal searches “was not so extensive as to trigger Fourth 

Amendment scrutiny.” Cleaveland, 38 F.3d at 1094.

The dissent notes that the government did nothing to 

discourage Yahoo’s internal searches and subsequent 

reports. True, but that is immaterial here. The Fourth 

Amendment does not require government officials to

discourage private actors from conducting searches that they 

have a legal basis to perform. Compare id. (“There was no 

reason why the detective should have restrained [the 

employee] or discouraged him in his search because [the 

employee] never exceeded his authority under the Customer 

Service Agreement to go on to the property and inspect the 

meter.” (cleaned up)); Miller, 688 F.2d at 657 (“Because 

[private actor] had not proposed to do anything illegal, we 

see no reason why the officers should have restrained him or 

discouraged him from visiting [suspect’s] property.”) with 

Walther, 652 F.2d at 793 & n.2 (finding acquiescence where 

the government did not discourage an informant from 

actively engaging in illegal searches with the expectation of 

a reward); United States v. Reed, 15 F.3d 928, 932 (9th Cir. 
UNITED STATES V. ROSENOW 23

1994) (finding acquiescence where the government “made 

no attempt to discourage” a hotel owner from searching 

“beyond what was required to protect hotel property.”).

The constitution limits the government. Nothing in our 

precedent establishes that a private party becomes a 

government actor simply because the government knows 

about and does not prevent such party from engaging in 

legally permissible conduct. This is particularly true where 

government actors are not even present during the search. Cf. 

Cleaveland, 38 F.3d at 1094; Reed, 15 F.3d at 932 (noting 

the significance of a “legitimate motive” for “private 

searches done in the presence of police officers” (emphasis 

added)). In the circumstances presented here, the 

government simply was not a “participant” or an 

“encourager” of the ESPs’ private conduct. Walther, 

652 F.2d at 791. In so holding, we do not suggest that 

government knowledge and acquiescence is established only 

if a private party’s conduct is illegal. We emphasize only that 

unless a private party’s search is illegal or based on an 

illegitimate motive, our precedent requires “active 

participation or encouragement” by the government before 

state action will be found. Id. at 792 (emphasis added).

ii. Private party’s intent

In analyzing the second requirement—the private party’s 

intent in searching—we look to whether it acted to “assist 

law enforcement efforts,” or whether it had a “legitimate, 

independent motivation to further its own ends.”

Cleaveland, 38 F.3d at 1094 (internal quotation marks and 

citation omitted). Under our precedent, a private party’s 

interest in preventing criminal activity, on its own, is not a 

legitimate, independent motivation to search. Reed, 15 F.3d 

at 932 (“[I]f crime prevention could be an independent 

private motive, searches by private parties would never 
24 UNITED STATES V. ROSENOW

trigger Fourth Amendment protection.”); but see Cameron, 

699 F.3d at 638 (“It is certainly the case that combating child 

pornography is a government interest. However, this does 

not mean that Yahoo cannot voluntarily choose to have the 

same interest.”). However, as long as a legitimate, 

independent motivation is established, “that motivation is 

not negated by any dual motive to detect or prevent crime or 

assist the police, or by the presence of the police nearby 

during the search.” Cleaveland, 38 F.3d at 1094.

Here, the record establishes that Yahoo and Facebook 

investigated Rosenow’s accounts to further their own 

legitimate, independent motivations. See Young, 153 F.3d 

at 1080–81. As the district court found, both companies have 

legitimate business reasons for purging child pornography 

and exploitation from their platforms, and they acted in 

furtherance of those reasons when they investigated 

Rosenow. Yahoo’s Director of Threat Investigations and 

Intelligence testified that it is “very bad for [Yahoo’s] brand”

if its services are viewed as “a haven for child pornography 

or child exploitation or sex trafficking.” He also stated that 

“[r]idding our products and services of child abuse images is 

critically important to protecting our users, our products, our 

brand, and our business interests.” Finally, he stated that 

Yahoo has a direct financial interest in keeping child 

pornography off its platforms because Yahoo does not want 

to lose advertising opportunities or be blocked from app 

stores.

A Facebook analyst familiar with that company’s 

internal search policies likewise explained that Facebook 

“has a business purpose in keeping its platform safe and free 

from harmful content and conduct . . . that sexually exploits 

children,” which is why Facebook prohibits “content that 

sexually exploits or endangers children.” She testified that 
UNITED STATES V. ROSENOW 25

Facebook’s policy of conducting limited review of accounts 

in cases indicating child exploitation is “to keep [its] 

platform safe and so users will continue to use [its] 

platform.”

This case is analogous to Cleaveland, where police

waited while an electricity company’s employee 

investigated the meter of a customer that was suspected of 

diverting power. 38 F.3d at 1093–94. The employee asked 

the police to accompany him to the customer’s home 

because of safety concerns and, “if his inspection uncovered 

the likelihood of a power diversion, he wanted the police to 

be able to get a warrant to search the house to confirm the 

power theft.” Id. at 1093. Although the police used evidence 

from the company’s search to obtain a warrant, we found 

insufficient government action to implicate the Fourth 

Amendment because, in part, the motive “to recover money 

for [the electricity company’s] loss of power” was a 

“legitimate, independent motive apart from” any interest in 

“assist[ing] the police in capturing the power thief.” Id. 

at 1094.

So, too, the ESPs’ desire to purge child pornography 

from their platforms and enforce the terms of their user 

agreements is a legitimate, independent motive apart from 

any interest that the ESPs had in assisting the government in 

apprehending Rosenow. In so holding, we again note that 

our decision is consistent with each of our sister circuits to 

have considered this issue. See Miller, 982 F.3d at 419 

(“Companies like Google have business reasons to make 

these efforts to remove child pornography from their 

systems.”); Ringland, 966 F.3d at 736 (“Google did not act 

as a government agent because it scanned its users’ emails 

volitionally and out of its own private business interests. 

Google did not become a government agent merely because 
26 UNITED STATES V. ROSENOW

it had a mutual interest in eradicating child pornography 

from its platform.”); Cameron, 699 F.3d at 638.

The dissent argues that Yahoo did not have an 

independent motivation for searching Rosenow’s account 

because, by failing to preserve images sent via its Messenger 

service, Yahoo could not close the account under its user 

agreement and, therefore, depended on law enforcement to 

further its interests. Dissent at 40–42. We disagree.

First, it was not a foregone conclusion at the outset of 

Yahoo’s search that it would not find any images that would 

permit it to close Rosenow’s account without law 

enforcement involvement. While Yahoo did not retain 

images sent through its Messenger service during the 

relevant period, it did retain its users’ Messenger profile 

pictures and images sent by users through its email service. 

Yahoo’s searches included these locations where images 

were retained. In fact, during the search activity that 

identified Rosenow, Yahoo found prohibited childexploitation images in other users’ email accounts and 

Messenger profile pictures, and it disabled those users’

accounts without any involvement by law enforcement.

Second, a private party’s otherwise legitimate, 

independent motivation is not rendered invalid just because 

law enforcement assistance may further its interests.5

5 In arguing otherwise, the dissent relies primarily on Ferguson, 

532 U.S. at 82–84. However, Ferguson concerned warrantless searches 

by state actors under the “special needs” exception to the warrant 

requirement. There, a state hospital adopted a “Management of Drug 

Abuse During Pregnancy” policy and attempted “to use the threat of 

arrest and prosecution in order to force women into [substance abuse] 

treatment.” Id. at 71–72, 84. Law enforcement had “extensive 

involvement” in developing the policy. Id. at 84. Of course, under such 
UNITED STATES V. ROSENOW 27

Cleaveland demonstrates this point. While the electric 

company had a legitimate business interest in preventing 

power theft, it specifically requested that law enforcement 

be present when it inspected its customer’s meter in part 

because it “wanted the police to be able to get a warrant and 

search the house to confirm the power theft.” 38 F.3d at 1093 

(emphasis added). This suggests that further action beyond 

its inspection of the meter was needed to either prevent 

further theft, recover against the customer, or both. Had the 

electric company been able to accomplish its business 

objective without assistance, it would not have needed law 

enforcement at the ready to get a warrant and search the 

customer’s home. Likewise, in Miller the private actor had 

an independent interest in recovering his stolen trailer, but 

he relied on law enforcement to act after he entered the 

defendant’s property and located his trailer.6 688 F.2d 

at 657–58.

Our conclusion is also consistent with Reed because 

there the hotel owner expressly admitted that his only

circumstances, the state may not rely on the “ultimate goal” of substance 

abuse treatment to justify warrantless searches. But Ferguson is flatly 

distinguishable from this case where a private actor is searching its own 

platform consistent with the terms of its user contract.

6 Even if were we to accept the dissent’s position that reliance on 

government assistance invalidates an otherwise legitimate, independent 

motivation, law enforcement intervention was not Yahoo’s only 

available means for preventing Rosenow from continuing to engage in 

prohibited conduct. Yahoo’s Director of Threat Investigations and 

Intelligence testified that the company has several ways to prevent child 

exploitation on its platform: deactivating accounts; making law 

enforcement referrals for arrests; and pursuing civil remedies, including 

lawsuits and “direct requests that [it] serve[s] via process servers to get 

people to stop engaging in activities.” Thus, Yahoo was not dependent 

on the government to further its goals.
28 UNITED STATES V. ROSENOW

motivation for searching the defendant’s room was to “help 

police gather proof that [the defendant] was using his room 

to deal narcotics.” 15 F.3d at 931. Unlike in Cleaveland and 

Miller, the hotel owner had no independent motivation for 

searching his customer’s room. However, in invalidating the 

search in that case, we indicated that if the hotel owner had 

entered the room for an independent purpose—such as 

ensuring that hotel property had not been damaged—and had 

not searched “beyond what was required to protect hotel 

property,” the search may not have been improper. See id. 

at 931.

For these reasons, we conclude that there was 

insufficient governmental involvement in Yahoo’s and 

Facebook’s private searches of Rosenow’s accounts to 

trigger Fourth Amendment protection.

2. Did the government’s preservation requests and 

subpoenas violate Rosenow’s right to privacy?

Rosenow also argues that he had a right to privacy in his 

digital data and that the government’s preservation requests 

and subpoenas, submitted without a warrant, violated the 

Fourth Amendment. We disagree.

a. Were the preservation requests unconstitutional 

seizures?

Acting pursuant to 18 U.S.C. § 2703(f), which requires 

an ESP “to preserve records and other evidence in its 

possession pending the issuance of a court order or other 

process,” the government directed Yahoo on three separate 

occasions to preserve records related to Rosenow’s private 

communications. Rosenow contends that these requests 

were an unconstitutional seizure of his property.
UNITED STATES V. ROSENOW 29

A “seizure” of property requires “some meaningful 

interference [by the government,] with an individual’s 

possessory interests in [his] property.” Jacobsen, 466 U.S. 

at 113. Here, the preservation requests themselves, which 

applied only retrospectively, did not meaningfully interfere 

with Rosenow’s possessory interests in his digital data 

because they did not prevent Rosenow from accessing his 

account. Nor did they provide the government with access to 

any of Rosenow’s digital information without further legal 

process. It also is worth noting that Rosenow consented to 

the ESPs honoring preservation requests from law 

enforcement under the ESPs’ terms of use. Thus, we agree 

with the district court that these requests did not amount to 

an unreasonable seizure in violation of the Fourth 

Amendment.

b. Was the subpoena an unconstitutional search?

In addition to the preservation requests, the government 

issued subpoenas to Facebook for Rosenow’s basic 

subscriber and IP information under 18 U.S.C. § 2703(c)(2). 

Relying on Carpenter, Rosenow contends that, because 

these subpoenas were issued without a warrant supported by 

probable cause, they were unconstitutional searches.

In addition to cabining “physical[] intru[sions] on a 

constitutionally protected area,” the Fourth Amendment 

protects “certain expectations of privacy.” Carpenter, 138 S. 

Ct. at 2213 (internal quotation marks and citation omitted). 

“When an individual seeks to preserve something as private, 

and his expectation of privacy is one that society is prepared 

to recognize as reasonable, we have held that official 

intrusion into that private sphere generally qualifies as a 

search and requires a warrant supported by probable cause.”

Id. (internal quotation marks and citation omitted). However, 

in what is commonly referred to as the third-party doctrine, 
30 UNITED STATES V. ROSENOW

the Supreme Court “consistently has held that a person has 

no legitimate expectation of privacy in information he 

voluntarily turns over to third parties.” Smith v. Maryland, 

442 U.S. 735, 743–44 (1979) (holding that the defendant had 

no reasonable expectation of privacy in the phone numbers 

he dialed from his home phone because he necessarily 

shared those numbers with the phone company to make a 

call); see United States v. Miller, 425 U.S. 435, 440–442 

(1976) (holding that the defendant had no reasonable 

expectation of privacy in his banking business records 

because he voluntarily shared that information with the 

bank).

In Carpenter, the Court declined to extend Smith and

Miller to a warrantless subpoena of cell phone site records, 

which revealed the defendant’s location over the course of 

127 days whenever he used his cell phone. 138 S. Ct. 

at 2212–14, 2217. Instead, the Court held that the subpoena 

seeking this information required a warrant, explaining that 

“an individual maintains a legitimate expectation of privacy 

in the record of his physical movements as captured through 

[cell phone surveillance technology]” even if that 

information is shared with third parties. Id. at 2217. 

Recognizing the intersection between the third-party 

doctrine and a separate line of cases addressing a person’s 

expectation of privacy in physical location and movements, 

the Court established that, “in the rare case where the suspect 

has a legitimate privacy interest in records held by a third 

party,” the government must obtain a warrant before issuing 

a subpoena absent exigent circumstances. Id. at 2215–16, 

2222–23. Rosenow argues that, under Carpenter, the 

government’s subpoenas directing Facebook to disclose his 

basic subscriber and log-in information violated the Fourth 
UNITED STATES V. ROSENOW 31

Amendment because he has a legitimate expectation of 

privacy in this digital data.7

But Carpenter is distinguishable.8 Unlike cell-site 

location, which implicates a long line of precedent 

recognizing a defendant’s reasonable “expectation of 

privacy in his physical location and movements,” id. at 2215, 

a defendant “ha[s] no expectation of privacy in . . . IP 

addresses” or basic subscriber information because internet 

users “should know that this information is provided to and 

used by Internet service providers for the specific purpose of 

directing the routing of information,” United States. v. 

Forrester, 512 F.3d 500, 510 (9thCir. 2008); see also United 

States v. Ulbricht, 858 F.3d 71, 97 (2d Cir. 2017), 

abrogation on other grounds recognized by United States v. 

Zodhiates, 901 F.3d 137, 143–44 (2d Cir. 2018);

9 United 

7 Rosenow also argues that he has a reasonable expectation of 

privacy in his private online messages. Because we conclude that 

Yahoo’s and Facebook’s searches of his messages were not 

governmental action, we need not reach this issue. See Jacobsen, 466 

U.S. at 113.

8 The Court in Carpenter emphasized that its holding was narrow, 

limited to the specific question presented in that case. 138 S. Ct. at 2220. 

We decline to broaden the application of Carpenter to the novel 

circumstances presented here.

9 In Ulbricht, the Second Circuit held first that it was bound by the 

broad rule that a party has no privacy interest in any information 

disclosed to third parties. 858 F.3d at 96–97. That court later recognized

that the Supreme Court has abrogated that rule, in part, in Carpenter. See 

Zodhiates, 901 F.3d at 143–44; United States v. Chambers, 751 F. App’x 

44, 46 (2d Cir. 2018). But Ulbricht also held, in the alternative, that even 

if the broad rule were abrogated in the future, the disclosure of IP 

addresses does not raise privacy concerns because “no reasonable person 

could maintain a privacy interest in that sort of information.” 858 F.3d 

at 97. We cite Ulbricht for that holding, which still stands.
32 UNITED STATES V. ROSENOW

States v. Caira, 833 F.3d 803, 806 (7th Cir. 2016). 

Specifically, in Forrester we analogized IP addresses and 

email to/from lines to the “information people put on the 

outside of mail,” which the Supreme Court has long held can 

be searched without a warrant because it “is voluntarily 

transmitted to third parties”; therefore, there is no legitimate 

expectation of privacy in such information. 512 F.3d at 511. 

This basic information differs from the content of email 

messages and other private communications, which are 

analogous to the sealed contents of mail, which the 

government does need a warrant to search. Id.

Here, the subpoenas did not request any communication 

content from Rosenow’s accounts, and the government did 

not receive any such content in response to its subpoenas. 

Everyone involved knew that additional legal process was 

required before the government could obtain that 

information. Thus, as in Forrester, Rosenow did not have a 

legitimate expectation of privacy in the limited digital data 

sought in the government’s subpoenas.

3. Did the search warrant lack probable cause?

Finally, Rosenow argues that the government’s search 

warrant affidavit failed to establish probable cause because 

it did not include any images of child pornography or any 

reasonable factual descriptions of such images.

Probable cause exists if, “based on the totality of the 

circumstances, there is a ‘fair probability’ that evidence of a 

crime may be found.” United States v. Perkins, 850 F.3d 

1109, 1119 (9th Cir. 2017) (citation omitted). Inclusion of 

illicit images is not required to establish probable cause. “[A] 

judge may properly issue a warrant based on factual 

descriptions of an image.” United States v. Battershell, 

457 F.3d 1048, 1052 (9th Cir. 2006).
UNITED STATES V. ROSENOW 33

Here, the government’s affidavit included excerpts from 

Rosenow’s messages with adolescent girls in the 

Philippines, demonstrating that he took and kept illicit 

pictures and videos of his sex tourism. For example, in one 

of Rosenow’s Facebook chats, he sends a girl nude photos 

he had previously taken of her and states, “I am always 

looking at your pictures on my phone . . . and I want more.”

In another chat, he negotiates sex acts with a girl and states, 

“baby, I want to take a video too.”

The affidavit also described Yahoo’s internal 

investigation and the resulting findings that Rosenow was 

negotiating, purchasing, and producing images and videos of 

child sexual exploitation, as well as the information that 

Facebook reported to NCMEC after searching Rosenow’s 

accounts. These descriptions include an account of 

Rosenow’s communications with girls in the Philippines, 

wherein Rosenow describes in graphic detail the sexual 

activities that he wanted to do with them and confirms that 

he wanted to record those activities.

In these circumstances, the omission of pornographic 

images was not an intentional misrepresentation or material 

omission. See Perkins, 850 F.3d at 1118–19 (finding agent 

acted improperly by withholding images in his possession 

and misrepresenting their content where there was a question 

whether the images were pornographic). Nor were the FBI 

agent’s multiple, detailed statements analyzing Rosenow’s 

messages and travel patterns merely “boilerplate 

description[s]” or “generalized statement[s]” of “a child 

pornography collector.” Id. at 1120. Thus, we conclude, as 

did the district court, that the affidavit supporting the search 

warrant established a “fair probability” that child 

pornography would be found on Rosenow’s electronic 

devices. See Illinois v. Gates, 462 U.S. 213, 238 (1983).
34 UNITED STATES V. ROSENOW

B. Jury Instructions

Rosenow argues that the jury was not properly instructed 

on Count 1—attempted sexual exploitation of a child in 

violation of 18 U.S.C. § 2251(c) and (e). A defendant 

violates § 2251(c)(1) if he “employs, uses, persuades, 

induces, entices, or coerces any minor to engage in . . . any 

sexually explicit conduct outside of the United States . . . for 

the purpose of producing any visual depiction of such 

conduct.” 18 U.S.C. § 2251(c)(1) (emphasis added). 

Rosenow requested an instruction stating that the “purpose”

element was satisfied only if the government proved that he 

“would not have acted but for his desire to produce a visual 

depiction of the sexually-explicit conduct.” The district court 

rejected Rosenow’s proposed instruction and instead 

instructed the jury that the government must prove that 

“producing a visual depiction of a minor engaged in sexually 

explicit conduct” was Rosenow’s “dominant, significant or 

motivating” purpose, not that it was his “sole purpose.”

Rosenow argues that the statutory phrase “for the 

purpose of” requires proof of both motive and but-for 

causation. He analogizes § 2251(c) to laws prohibiting 

adverse employment actions “because of” or “based on”

discriminatory motives. See, e.g., Burrage v. United States, 

571 U.S. 204, 213–14 (2014) (noting statutory phrases in 

discrimination statutes indicate “but-for” causal links).

But-for causation is required “when a crime is defined in 

terms of conduct causing a particular result.” Id. at 211 

(internal quotation marks and citation omitted). In Burrage, 

the Court analyzed a statutory penalty enhancement for drug 

offenses where “death or serious bodily injury results from”

a defendant’s conduct. Id. at 206 (internal quotation marks 

and citation omitted). The Court concluded that the “results 

from” phrase required a causal link between the harm (death 
UNITED STATES V. ROSENOW 35

or injury) and the proscribed conduct (drug offense). See id. 

at 211–13. Likewise, employment statutes often link the 

harm (adverse employment action) taken “because of” the 

proscribed conduct (discriminatory motives). Id. But here, 

the harm (production of obscene content) and the proscribed 

conduct (enticing children to engage in it) are not connected 

by any causal link in the text of the statute; rather, the harm 

and the conduct are connected by the defendant’s “purpose.”

18 U.S.C. § 2251(c). Thus, we see no basis to conclude that 

“purpose,” as used in § 2251, has a causal or results 

requirement.

Our precedent further undermines Rosenow’s reading of 

Burrage. In Rodriguez, albeit interpreting another statute, 

we held that the “‘results from’ language evaluated in 

Burrage differs materially from the ‘for the purpose of’

language . . . . The latter phrase concerns motive whereas the 

former concerns causation.” 971 F.3d at 1010. Similarly, in 

United States v. Lindsay, we found no “obvious error” where 

the district court instructed the jury to apply the “dominant, 

significant, or motivating” standard to an offense prohibiting 

travel “for the purpose of” engaging in illicit sex. 931 F.3d 

852, 864 (9th Cir. 2019).

In sum, we conclude that the jury was properly instructed 

on Count 1.

C. Sentencing Calculation

Finally, Rosenow argues that the district court 

improperly sentenced him as if he had been convicted on 

multiple counts of possession of child pornography when he 

was convicted on only one count.

When more than one minor is exploited in an offense 

where the defendant “caus[ed], transport[ed], permit[ed], or 
36 UNITED STATES V. ROSENOW

offer[ed] or s[ought] by notice or advertisement, a minor to 

engage in sexually explicit conduct for the purpose of 

producing [child pornography],” the Sentencing Guidelines 

direct the district court to apply the guidelines applicable to 

multiple counts “as if the exploitation of each minor had 

been contained in a separate count of conviction.” U.S.S.G. 

§§ 2G2.1(d)(1), 2G2.2(c)(1). At trial, Rosenow stipulated 

that he knowingly possessed five depictions of child 

pornography, including two videos showing himself 

engaging in sexually explicit conduct with four different 

minors. The jury convicted Rosenow of one count of 

knowing possession “with intent to view, 1 or more books, 

magazines, periodicals, films, video tapes, or other matter 

which contain any visual depiction” of child pornography. 

18 U.S.C. § 2252(a)(4)(B).

The district court found, based on Rosenow’s 

stipulations at trial, that in committing the possession 

offense, Rosenow caused a minor to engage in sexually 

explicit conduct “for the purpose of producing a visual 

depiction of that conduct.” U.S.S.G. § 2G2.2(c)(1). 

Accordingly, the court applied the Sentencing Guidelines’

multiple-count instruction and calculated Rosenow’s 

sentence based on the exploitation of four separate victims, 

which increased Rosenow’s base offense level and doubled 

his guideline range.

In arguing that this calculation was error, Rosenow relies 

primarily on Chilaca, where we interpreted 

§ 2252(a)(4)(B)’s prohibition against possession of “1 or 

more” depictions of child pornography “to mean that the 

simultaneous possession of different matters containing 

offending images at a single time and place constitutes a 

single violation of the statute.” 909 F.3d at 295. The 

defendant in that case was charged with four counts under 
UNITED STATES V. ROSENOW 37

§ 2252(a)(4)(B), but it was undisputed that he 

simultaneously possessed all the images identified in the 

four separate counts. Id. at 291, 295. Thus, we vacated three 

counts as multiplicitous. Id. at 295, 297.

Chilaca does not control this case. The defendant in 

Chilaca was charged with and convicted of four counts for 

the single act of possessing “1 or more” depictions of child 

pornography. Id. at 295. Here, Rosenow was convicted of a 

single offense of possession which involved the exploitation 

of several child victims. That is, there was no double 

counting when the district court applied the Sentencing 

Guidelines’ instructions regarding multiple minor victims, 

as the enhancements were premised on separate exploitative 

acts.

The Sentencing Commission “plainly understands the 

concept of double counting, and expressly forbids it where it 

is not intended.” United States v. Reese, 2 F.3d 870, 894 (9th 

Cir. 1993) (quoting United States v. Williams, 954 F.2d 204, 

208 (4th Cir. 1992)). But applying multiple enhancements 

based on the same conduct is presumptively permissible 

under the Sentencing Guidelines. See U.S.S.G. § 1B1.1 

comment. n.4(B) (“Absent an instruction to the contrary, 

enhancements . . . are to be applied cumulatively . . . [and] 

may be triggered by the same conduct.”). And here, the 

enhancement imposed is not only permitted by the 

Sentencing Guidelines—it is required. Id. § 2G2.1(d)(1). 

The Sentencing Guidelines’ application notes explain that 

“each minor exploited is to be treated as a separate minor,”

“multiple counts involving the exploitation of different 

minors are not to be grouped together,” and “each such 

minor shall be treated as if contained in a separate count.”

Id. § 2G2.1 comment. 7.
38 UNITED STATES V. ROSENOW

Because the Sentencing Guidelines are clear that 

punishment is to account for the number of child victims 

exploited in the production of child pornography, we find no 

error in the district court’s sentencing calculation.

AFFIRMED.

GRABER, Circuit Judge, dissenting in part:

With one exception, I concur in full in the majority 

opinion. I agree with the majority opinion’s analysis of 

Defendant’s challenges to the jury instructions and to the 

sentencing calculation. I also agree with most of the 

majority opinion’s analysis of the Fourth Amendment 

issues. In particular, I agree that federal law alone did not 

transform Yahoo’s or Facebook’s searches into 

governmental action; that the government did not actively 

participate in Yahoo’s or Facebook’s searches; that 

Facebook’s searches did not implicate the Fourth 

Amendment; and that the government’s preservation 

requests and subpoenas did not violate Defendant’s right to 

privacy. I part ways only as to the question whether, in 

conducting its searches of Defendant’s chat messages, 

Yahoo was acting as an instrument or agent of the 

government. On that issue, I respectfully dissent.

“The Fourth Amendment limits searches conducted by 

the government, not by a private party, unless the private 

party acts as an ‘instrument or agent’ of the government.” 

United States v. Young, 153 F.3d 1079, 1080 (9th Cir. 1998) 

(per curiam). “Whether a search is governmental or private 

depends on: (1) whether the government knew of and 

acquiesced in the intrusive conduct; and (2) whether the 
UNITED STATES V. ROSENOW 39

party performing the search intended to assist law 

enforcement efforts or further the party’s own ends.” Id.

1. Did the government know of and acquiesce in Yahoo’s 

intrusive conduct?

Here, the government knew of and acquiesced in 

Yahoo’s searches of chat messages. Beginning early in the 

course of Yahoo’s investigation, government agents hosted 

several meetings with Yahoo’s lead investigator, who 

relayed to the government agents detailed and extensive 

search results and independent analysis. In the very first 

meeting, Yahoo’s investigator described to the government 

agents the tools that Yahoo was using to view snippets of 

private chat messages sent by individual users. The 

government agents took no action to discourage the searches 

or reports. Notably, the district court did not find that the 

government lacked knowledge about, or failed to acquiesce 

in, Yahoo’s searches.

The majority opinion, while agreeing that the 

government knew about and failed to discourage Yahoo’s 

searches, asserts that these facts are “immaterial.” Op. at 22.

Not so. Young asks “whether the government knew of and 

acquiesced in the intrusive conduct.” 153 F.3d at 1080 

(emphases added). The government’s implied consent to 

Yahoo’s intrusive conduct is the very essence of 

acquiescence.

The majority opinion also seems to suggest—despite its 

assertion to the contrary—that this prong is not met because 

Yahoo’s searches were legal and that the test would be met 

only if Yahoo’s conduct had been illegal. Op. at 22–23. 

That proposition is illogical; the government is more likely 

to acquiesce in legal conduct than in illegal conduct. 

Perhaps more to the point, the majority opinion’s suggestion 
40 UNITED STATES V. ROSENOW

is contradicted by our precedents. In United States v. 

Cleaveland, 38 F.3d 1092 (9th Cir. 1994), the employee’s 

search was legal; nonetheless we held that “the police knew 

of and acquiesced in [the employee’s] search of the meter at 

Cleaveland’s house.” Id. at 1094. That is, the first prong 

was met. The same is true of United States v. Miller, 688 

F.2d 652 (9th Cir. 1982). The private party’s search was 

legal, but we agreed that the police officers “knew of and 

acquiesced in [the private person’s] conduct.” Id. at 657. 

That is, the first prong was met.

2. Did Yahoo intend to assist law enforcement or to further 

its own ends?

The second prong queries the private party’s motivation. 

If the private party “had a ‘legitimate, independent 

motivation’ to further its own ends,” then the search does not 

implicate the Fourth Amendment. Cleaveland, 38 F.3d 

at 1094 (citing United States v. Walther, 652 F.2d 788, 792 

(9th Cir. 1981); United States v. Reed, 15 F.3d 928, 931 (9th 

Cir. 1994)). That conclusion remains true even if the private 

party had a “dual motive to detect or prevent crime or assist 

the police.” Id. But if the private party had no “legitimate 

independent motivation,” then the second prong—an 

intention to aid law enforcement—is met. Reed, 15 F.3d 

at 932.

Here, as the majority opinion explains, Facebook had a 

legitimate, independent motivation in conducting its 

searches. Op. at 24–25. Facebook’s terms of use prohibit 

content that sexually exploits or endangers children, and 

Facebook may close any account that violates the terms of 

use. Indeed, as a result of Facebook’s searches of 

Defendant’s account, Facebook did close his account.
UNITED STATES V. ROSENOW 41

The analysis of Yahoo’s searches of Defendant’s chat 

messages differs. As the district court properly found, 

Yahoo had a legitimate reputational interest in preventing its 

services from being used to exploit or abuse children. But, 

under the specific facts of this case, that legitimate interest 

was dependent on—not independent from—governmental 

action.

It is undisputed that, during the relevant period, Yahoo 

did not store “photographs or videos or other files shared 

between two users” via its Messenger chat application. 

Indeed, any videos or images sent via the Messenger chat 

application were “never transmitted [to] Yahoo servers, so 

there was no record of any file transfer of videos or images 

that would have been available for [Yahoo’s] review.” At 

all relevant times, Yahoo’s policy allowed Yahoo to 

terminate a user’s account on the ground of child 

exploitation only if it discovered actual images or videos of 

child pornography. Despite that clear limitation, Yahoo’s 

investigators used internal tools to review Defendant’s “full 

chat history on the Yahoo Messenger” and reported many 

chat snippets verbatim to the government. Yahoo’s 

investigators “determined that pulling the content, reviewing 

it, and then filing [reports to the government] might be a way 

to get the [suspected child-abuse] activity to stop.” When 

asked whether the mechanism for stopping the activity was 

helping to provide “probable cause” to federal law 

enforcement, Yahoo’s lead investigator replied in the 

affirmative. And he acknowledged that, although his team 

did not exist “only . . . to have a bad guy arrested,” that is 

one of the outcomes that the team strives for.

Putting it together, Yahoo’s review of Defendant’s chat 

messages could not possibly have led to Yahoo’s termination 

of Defendant’s account. The only means by which to 
42 UNITED STATES V. ROSENOW

prevent Defendant’s unlawful conduct was (as the 

government puts it) “inviting a law enforcement response”

and ensuring a successful prosecution. As the government 

concedes in its brief: “Despite his misuse of its platform, 

Yahoo never terminated [Defendant’s] Yahoo Messenger 

account since no actual child pornography images were 

found on it.” In other words, protecting Yahoo’s legitimate 

reputational interest required the assistance of the federal 

government. Cf. Ferguson v. City of Charleston, 532 U.S. 

67, 82–84 (2001) (rejecting, as part of an analysis of the 

“special needs” exception, the government’s attempt to 

define the purpose of a search in terms of its “ultimate goal”

of helping women and children rather than its “immediate 

objective” of generating “evidence for law enforcement 

purposes”). The majority opinion states that Yahoo had 

other available means to prevent Defendant from continuing 

his activities on Yahoo. Op. at 27 n.6. That may be so in 

theory, but Yahoo’s representative testified that Yahoo could 

not shut down Defendant’s account for violating the 

platform’s terms and conditions because there were no 

images or videos of child pornography on any of his

accounts. The facts in some other case could differ and 

could yield a different result, but in this instance Yahoo’s 

legitimate motive was not independent. Yahoo could not, on 

the particular facts of this case, achieve its legitimate 

corporate objective without the prosecutorial efforts of law 

enforcement.

Our decision in Cleaveland, 38 F.3d at 1093–94, 

supports that conclusion. The power company in 

Cleaveland suspected that a customer was diverting 

electricity illegally, thus preventing the company from 

collecting the full amount that the customer owed. Id.

at 1093. An employee for the power company entered the 

defendant’s property to inspect the electricity meter, and he 
UNITED STATES V. ROSENOW 43

discovered wires diverting electricity. Id. The employee 

“had authority to do this pursuant to [the power company’s] 

Customer Service Agreement.” Id. We concluded that the 

private search did not implicate the Fourth Amendment for 

the following reason: “While [the employee] may have had 

dual motives for conducting the search—to recover money 

for [the company’s] loss of power on the one hand, and to 

assist the police in capturing the power thief (and perhaps 

uncovering a marijuana grow) on the other—his motive to 

recover for [the company’s] loss of power was a legitimate, 

independent motive apart from crime detection or 

prevention.” Id. at 1094 (emphasis added). Unlike in 

Cleaveland, Yahoo’s reputational motive here in searching 

Defendant’s chat messages was necessarily dependent on 

law enforcement efforts. See also Reed, 15 F.3d at 932 

(holding that, in opening a briefcase and dresser drawer, the 

private party “had no legitimate independent motive within 

the meaning of [this court’s] cases; ‘snooping’ is not a 

legitimate motive and finding evidence of criminal activity 

is not independent”).

The majority opinion suggests that Cleaveland and 

Miller support its holding. Op. at 25–28. But the power 

company in Cleaveland and the victim of theft in Miller

didn’t care—as far as the opinions suggest—whether the 

government prosecuted the criminals. They just wanted the 

money they were owed or the return of their stolen trailer. 

What makes this situation different is that Yahoo had no way 

to advance its reputational interest unless the government 

prosecuted Defendant. And what makes this case more like 

Reed is that, in practical terms, Yahoo’s motivation was to 

help law enforcement gather proof for a prosecution. That 

is, while Yahoo’s motive was without question legitimate, in 

the circumstances it was not independent. Because Yahoo’s 

motivation to conduct the searches was intertwined with, and 
44 UNITED STATES V. ROSENOW

dependent on, the government’s enforcement of criminal 

laws, the second prong of the “instrument or agent” analysis 

is met with respect to Yahoo’s searches of Defendant’s chat 

messages.

3. Conclusion

Because I conclude that Yahoo’s searches of 

Defendant’s chat messages implicated the Fourth 

Amendment, I would vacate the district court’s order 

denying Defendant’s motion to suppress and remand for the 

court’s consideration, in the first instance, all related issues, 

including whether any error was harmless, whether the 

good-faith exception applies, and whether suppression is an 

appropriate remedy in this case.

In analyzing whether Yahoo acted as an “agent or 

instrument” of the government, we are bound by our 

precedents that establish the two-part test described above. 

Miller v. Gammie, 335 F.3d 889, 899–900 (9th Cir. 2003) 

(en banc). As a three-judge panel, we therefore may not 

consider Defendant’s assertion that our test is too rigid and 

fails to account for the considerable intrusiveness of Yahoo’s 

searches. In an appropriate case, the en banc court might 

consider whether our test—which developed in the context 

of searches of, for example, a briefcase, an electricity meter, 

or a single parcel of property—warrants reconsideration in 

light of technological developments in the intervening 

decades. Cf. Carpenter v. United States, 138 S. Ct. 2206, 

2217–18 (2018) (considering in detail the differences for 

Fourth Amendment purposes between cell phone tracking in 

“the digital age” as “compared to traditional investigative 

tools”); Riley v. California, 573 U.S. 373 (2014) (rejecting 

the argument that prior precedent controlled the Fourth 

Amendment analysis as to cell phones because “[t]hat is like 
UNITED STATES V. ROSENOW 45

saying a ride on horseback is materially indistinguishable 

from a flight to the moon”).1

1 As an example pertinent here, in 1982, we held that the 

government’s acquiescence in a private person’s physical search of a 

parcel of land in Montana for a stolen trailer did not violate the Fourth 

Amendment. Miller, 688 F.2d at 656–58. I wonder whether we likewise 

would approve, as consistent with the Fourth Amendment, the 

government’s acquiescence in a private person’s plan to use a bevy of 

drones to search thousands of private parcels throughout the state.