## Facts

- An anonymous hacker (“Unknownuser”) used a Trojan horse method to access computers of suspected child pornographers and provide copied files to U.S. law enforcement.
- Before the events involving William Adderson Jarrett, Unknownuser had assisted law enforcement in an unrelated child-pornography investigation; agents expressed appreciation, sought cooperation, and discussed non-prosecution, but did not direct specific future intrusions.
- Unknownuser later used the same Trojan horse method to obtain undetected access to Jarrett’s computer after Jarrett downloaded a file containing the Trojan program.
- Unknownuser located apparent child-pornography files on Jarrett’s computer and transmitted copies and identifying information to law enforcement.
- Using the hacker-provided information, agents obtained a search warrant, searched Jarrett’s residence and equipment, seized evidence, and Jarrett was indicted on federal child-pornography offenses.
- Jarrett moved to suppress, arguing Unknownuser acted as a government agent, making the intrusion a warrantless government search under the Fourth Amendment.
- The district court agreed and suppressed the evidence; the United States appealed under 18 U.S.C. § 3731.

## Issues

1. Whether a hacker’s warrantless intrusion into a defendant’s computer is attributable to the government for Fourth Amendment purposes when the hacker previously cooperated with law enforcement but the government lacked contemporaneous knowledge of the intrusion and did not direct it.

## Decision

- The Fourth Circuit reversed the suppression order and remanded.
- The court held Unknownuser was not acting as a government agent when he intruded into Jarrett’s computer because the government did not know of, participate in, or instigate that search at the time it occurred.
- Because the initial intrusion was a private search, the Fourth Amendment did not apply, and evidence obtained pursuant to the later warrant was not subject to suppression on that ground.

## Legal Principles

- The Fourth Amendment restricts governmental, not purely private, searches.
- A private party is treated as a government agent for Fourth Amendment purposes only if: (1) the government knew of and acquiesced in the intrusive conduct, and (2) the private party intended to assist law enforcement.
- Government knowledge and acquiescence at the time of the search are required; a private actor’s intent to help law enforcement is insufficient by itself.
- Prior cooperation, expressions of gratitude, or passive acceptance of a private party’s activities do not create an ongoing agency relationship absent government direction, control, or contemporaneous participation in the challenged search.
- Later government use of privately obtained information to seek a warrant does not retroactively convert the earlier private search into governmental action.

## Conclusion

The Fourth Circuit ruled that a hacker’s computer intrusion remained a private search where law enforcement neither knew of nor participated in the intrusion when it occurred, so the Fourth Amendment did not require suppression of evidence later obtained under a warrant based on the hacker’s tip.


United States v. Jarrett, 338 F.3d 339 (4th Cir. 2003)