[JURIST] The American Civil Liberties Union (ACLU) [advocacy website] filed a lawsuit [press release] on Wednesday under the Freedom of Information Act (FOIA) [materials] to compel the FBI [official website] to release two memoranda detailing the agency’s policy on GPS tracking. The ACLU asserts that the memos were written shortly following the US Supreme Court [official website] decision [text, PDF; JURIST report] United States v. Jones [SCOTUSblog backgrounder], which held that monitoring a vehicle with a GPS device constitutes a search under the Fourth Amendment [text]. In its press release, the ACLU argued that the Supreme Court’s decision in Jones left several legal issues unresolved and that the FBI’s memos may provide valuable insight on these issues:

The two memos we’ve asked for may show how the FBI has resolved these unanswered questions. We know about the memos’ existence from a talk given by FBI General Counsel Andrew Weissmann in February. He said that one memo focuses exclusively on the use of GPS tracking, and suggested that it covers questions like whether Jones applies to other forms of transportation like airplanes and boats, and whether it applies at international borders.

Congress is currently considering an ACLU-backed bill entitled the Geolocation Privacy and Surveillance Act (GPS Act) [text] that would require law enforcement officials to obtain a warrant before searching a suspect’s GPS or cell phone.

Government use of modern technology to monitor and locate citizens has created legal uncertainty recently. Earlier this week the US Court of Appeals for the Sixth Circuit [official website] ruled [JURIST report] that police tracking of GPS devices in suspects’ cell phones does not constitute an illegal search under the Fourth Amendment. Earlier in August, the ACLU announced that their affiliates are sending approximately 375 requests for information in 31 states to reveal how law enforcement uses location data tracking on cell phones [JURIST report], arguing that the warrantless tracking of GPS signals is unconstitutional. In June lawyers for the US Department of Justice defended the warrantless use of GPS devices [JURIST report] on suspects’ vehicles despite the Supreme Court ruling in Jones declaring GPS tracking to be a “search” under the Fourth Amendment. The Supreme Court concluded in Jones that the government’s attachment of a GPS device to a vehicle, and its use of that device to monitor the vehicle’s movements, constitutes a search under the Fourth Amendment. Also in January the Supreme Court of California ruled that law enforcement officers can legally search text messages [JURIST report] on a suspect’s cell phone without a warrant incident to a lawful custodial arrest.