People v. Evensen
4 Cal. App. 5th 1020
| Cal. Ct. App. | 2016Background
- Police used RoundUp, a law-enforcement tool that searches public peer-to-peer (P2P) networks for files whose hashes match known child‑pornography images; RoundUp reports IP addresses that shared or downloaded those files.
- RoundUp flagged an IP address with many hits; public records showed the IP provider was Comcast; a Comcast records warrant identified the subscriber as defendant Evensen’s mother.
- Police obtained a warrant for the mother’s home; Evensen was present, arrested, and confessed to possessing and obtaining child pornography via P2P software (eMule); forensic exam revealed >200 videos/images.
- After the arrest additional sexual‑assault allegations and victims were identified from seized material; Evensen pleaded no contest to multiple sex‑crime counts and was sentenced.
- Evensen moved to suppress, arguing RoundUp’s use constituted an unconstitutional Fourth Amendment search of his computer; the trial court denied the motion and the appellate court affirmed.
Issues
| Issue | Plaintiff's Argument | Defendant's Argument | Held |
|---|---|---|---|
| Whether use of RoundUp to detect file‑sharing of known child‑pornography images was a Fourth Amendment search requiring suppression | RoundUp searched a public P2P network to identify IPs sharing contraband; results provided probable cause for warrants | Evensen claimed a subjective and objectively reasonable expectation of privacy in his computer/shared folder; RoundUp’s use (and police‑only tech) infringed that privacy | Court held no reasonable expectation of privacy in files placed in a publicly accessible P2P shared folder; use of RoundUp was not a Fourth Amendment search requiring suppression |
| Whether defendant’s efforts to limit sharing changed the analysis | Plaintiff argued exposure via P2P negates privacy despite selective or imperfect privacy settings | Evensen argued he modified settings, moved files off shared folder, and limited upload availability so he reasonably expected privacy | Court found substantial evidence he did not consistently prevent sharing; RoundUp detects only files in shared folders, so his measures did not create an objectively reasonable expectation of privacy |
| Whether RoundUp’s use is analogous to warrantless use of advanced, non‑public surveillance tech (Kyllo) | Plaintiff argued RoundUp monitors public network activity, not interior home details otherwise unknowable without physical intrusion | Evensen argued RoundUp is specialized, non‑public sense‑enhancing tech akin to thermal imaging in Kyllo | Court distinguished Kyllo: RoundUp observes activity on a public P2P network (exposed to others), not previously unknowable details of the home |
| Whether RoundUp’s report provided stale or insufficient probable cause for the warrants | Plaintiff argued RoundUp’s history reporting of known hashes provided a fair probability evidence remained at premises | Evensen argued data was historic and stale (last seen months earlier) | Court rejected staleness claim (also found forfeited procedurally) and held RoundUp’s report furnished probable cause for the warrants |
Key Cases Cited
- United States v. Ganoe, 538 F.3d 1117 (9th Cir. 2008) (no reasonable expectation of privacy for files knowingly shared via P2P software)
- United States v. Borowy, 595 F.3d 1045 (9th Cir. 2010) (same: exposure via file‑sharing negates objective privacy even if user tried to limit sharing)
- Kyllo v. United States, 533 U.S. 27 (2001) (use of sense‑enhancing device to obtain details of the home not otherwise observable is a search)
- Katz v. United States, 389 U.S. 347 (1967) (Fourth Amendment protects reasonable expectation of privacy)
- Illinois v. Gates, 462 U.S. 213 (1983) (probable cause standard for warrants based on totality of the circumstances)
- People v. Williams, 45 Cal.3d 1268 (1988) (standards of review for suppression rulings)
- People v. Camarella, 54 Cal.3d 592 (1991) (probable cause exists when there is a fair probability evidence will be found)