United States v. Daigle

CourtCourt of Appeals for the First Circuit
DecidedJune 10, 2026
Docket24-1889
StatusPublished

This text of United States v. Daigle (United States v. Daigle) is published on Counsel Stack Legal Research, covering Court of Appeals for the First Circuit primary law. Counsel Stack provides free access to over 12 million legal documents including statutes, case law, regulations, and constitutions.

Bluebook
United States v. Daigle, (1st Cir. 2026).

Opinion

United States Court of Appeals For the First Circuit

No. 24-1889

UNITED STATES OF AMERICA,

Appellee,

v.

ROBERT DAIGLE,

Defendant, Appellant.

APPEAL FROM THE UNITED STATES DISTRICT COURT FOR THE DISTRICT OF MASSACHUSETTS

[Hon. Nathaniel M. Gorton, U.S. District Judge]

Before

Barron, Chief Judge, Lipez and Rikelman, Circuit Judges.

Zainabu Rumala, Assistant Federal Public Defender, for appellant. Randall E. Kromm, Assistant United States Attorney, with whom Leah B. Foley, United States Attorney, was on brief, for appellee.

June 10, 2026 RIKELMAN, Circuit Judge. Robert Daigle appeals the

denial of his motion to suppress evidence discovered in a search

of his home. According to Daigle, the government did not establish

probable cause to believe that child pornography would be found on

his home computer at the time of the search. The district court

concluded otherwise, relying on facts showing that, nine months

earlier, a computer with an IP address tied to Daigle's residence

had logged requests on a specialized network for three electronic

files that contained child pornography, all within ten minutes.

We conclude that these facts were sufficient to meet the probable

cause standard and thus affirm.

I. BACKGROUND

A. Relevant Facts

This case arises from a decade-long investigation by law

enforcement into Freenet, a peer-to-peer network that "allows

users to anonymously share files, chat on message boards, and

access websites within the network." To put the legal issues in

context, we recount the basic mechanics of Freenet, as well as the

events that led the government to Daigle. We draw the facts from

the search warrant affidavit submitted in this case by Special

Agent Brian O'Sullivan of the Federal Bureau of Investigation

(FBI).

- 2 - 1. The Mechanics of Freenet

To access the Freenet network, "a user must first

download the Freenet software, which is free and publicly

available." A computer running the Freenet software "connects

directly to other computers running Freenet, which are called its

'peers.'" When a user installs Freenet, they "agree[] to provide

to the network a portion of the storage space on [their] computer

hard drive, so that files uploaded by Freenet users can be

distributed and stored across the network."

Once a user uploads a file to Freenet, "the software

breaks the file into pieces (called 'blocks') and encrypts each

piece." These encrypted blocks are then "distributed randomly"

and stored by peer computers. Freenet creates an "index piece,"

which contains a list of all the file's blocks, and assigns a

"unique key -- a series of letters, numbers and special

characters" -- to the file.

To download a file on Freenet, a user must have the key

associated with that file. When a user tries to download a file,

Freenet requests that file's blocks from other computers running

the Freenet software (the peers). Instead of requesting all the

blocks from one peer, Freenet "divide[s] up" the block requests

"in roughly equal amounts among the user's peers." If a peer

computer does not have the requested blocks, that peer will divide

up the request and ask additional peers for the missing blocks,

- 3 - and so on. Critically, just because a user requests a file does

not guarantee that they can retrieve the blocks for that file or

download it.

Freenet's design "attempts to hide" which user uploaded

or downloaded a file "by making it difficult to differentiate"

between the original requestor of a file and a peer who simply

forwarded another peer's request for that file. Still, "Freenet

warns its users in multiple ways that it does not guarantee

anonymity," including by explaining on its public website that it

does not mask a computer's IP address.

Although Freenet is not dedicated to child pornography,

users can "advertise and distribute images and videos of child

pornography" on the network.1 Importantly, Freenet does not offer

a search function, meaning that a user in search of child

pornography must first identify the key for a specific file and

then use that key to download the file. To obtain such a key,

Freenet users can go to "message boards" on the network, where

other users might post messages related to child pornography.

These message boards often have labels that are suggestive of the

1A peer-reviewed, publicly available academic paper studied 70,000 keys "posted to forums [on Freenet] openly dedicated to child sexual exploitation and confirmed to include known [child pornography] images." Brian N. Levine et al., Statistical Detection of Downloaders in Freenet, Procs. Inst. of Elec. & Elecs. Eng'rs Int'l Workshop on Priv. Eng'g, May 2017, at 8. That study determined that approximately 35% of Freenet's overall traffic related to requests for files using those keys. See id.

- 4 - sexual exploitation of children. Freenet users can also access

websites that only operate within the network, known as

"Freesites." Certain Freesites contain viewable images of child

pornography, along with keys related to child pornography files.

To support investigations into the sharing of child

pornography on Freenet, law enforcement officers have access to a

modified version of the Freenet software, which has been loaded

onto government computers. This modified version is "nearly

identical to Freenet," except that it permits officers to track

certain information about each request for file blocks that

government computers receive from Freenet users. This information

includes the requesting user's IP address.

Law enforcement officers "do not target specific peers

on Freenet nor do [they] solicit requests from any peers." Rather,

they "collect keys associated with suspected child pornography

files" and only investigate Freenet users who use those keys to

request files. Officers obtain such keys from Freenet message

boards, Freesites, and their prior investigations.

A peer-reviewed, publicly available academic paper

describes a mathematical formula for determining whether a request

for a file of interest originated from a given computer. See Brian

N. Levine et al., Statistical Detection of Downloaders in Freenet,

Procs. Inst. of Elec. & Elecs. Eng'rs Int'l Workshop on Priv.

Eng'g, May 2017, at 8. Based on his training and experience,

- 5 - O'Sullivan "believe[d] [the formula] to be a reliable method" for

law enforcement officers to use in identifying which computer on

the Freenet network initiated a request for child pornography

files.

2. The Investigation

Using their modified version of Freenet, law enforcement

officers identified a computer with an IP address of 96.230.244.94,

which was running the Freenet software. Within a ten-minute

timeframe, the user of that computer had requested the blocks of

three different files. Officers knew that each of those three

files contained child pornography. They had acquired the keys for

the three files from various sources: a Freenet message board, a

Freesite, and a previous investigation. But they were "not aware

Free access — add to your briefcase to read the full text and ask questions with AI

Related

United States v. Vosburgh
602 F.3d 512 (Third Circuit, 2010)
United States v. Falso
544 F.3d 110 (Second Circuit, 2008)
Franks v. Delaware
438 U.S. 154 (Supreme Court, 1978)
Illinois v. Gates
462 U.S. 213 (Supreme Court, 1983)
United States v. Zayas-Diaz
95 F.3d 105 (First Circuit, 1996)
United States v. Morales-Aldahondo
524 F.3d 115 (First Circuit, 2008)
United States v. Peter John Weber
923 F.2d 1338 (Ninth Circuit, 1991)
United States v. Micah J. Gourde
440 F.3d 1065 (Ninth Circuit, 2006)
United States v. McLellan
792 F.3d 200 (First Circuit, 2015)
United States v. Flores
888 F.3d 537 (First Circuit, 2018)
United States v. Anzalone
923 F.3d 1 (First Circuit, 2019)
United States v. Roman
942 F.3d 43 (First Circuit, 2019)
United States v. Raymonda
780 F.3d 105 (Second Circuit, 2015)
United States v. Sylvestre
78 F.4th 28 (First Circuit, 2023)
United States v. Cortez
108 F.4th 1 (First Circuit, 2024)
United States v. Gonzalez
113 F.4th 140 (First Circuit, 2024)

Cite This Page — Counsel Stack

Bluebook (online)
United States v. Daigle, Counsel Stack Legal Research, https://law.counselstack.com/opinion/united-states-v-daigle-ca1-2026.