Supreme Court says search warrants needed when police use GPS devices to track suspects - The Washington Post
http://www.washingtonpost.com/business/technology/supreme-court-says-search-warrants-needed-when-police-use-gps-devices-to-track-suspects/2012/01/23/gIQA7wL1KQ_story.html
The Supreme Court ruled unanimously Monday that police must get a search warrant before using GPS technology to track criminal suspects.
(...) Associate Justice Antonin Scalia said that the government’s installation of a GPS device, and its use to monitor the vehicle’s movements, constitutes a search, meaning that a warrant is required.