The Supreme Court of United States decided a case today that will now require police officers to obtain a warrant (except in exigent circumstances) before collecting cell phone location data from cell phone companies.
Prior to this ruling, the government was allowed to collect cell phone data from companies like AT&T and Verizon with a simple request. This data contained minute-by-minute GPS location data. Officers then used this data as evidence to try to make a case against suspects.
Chief Justice Roberts wrote, "We decline to grant the state unrestricted access to a wireless carrier’s database of physical location information. In light of the deeply revealing nature of [this information], its depth, breadth, and comprehensive reach, and the inescapable and automatic nature of its collection, the fact that such information is gathered by a third party does not make it any less deserving of Fourth Amendment protection. The Government’s acquisition of the cell-site records here was a search under that Amendment."
This ruling is a small victory in the defense of privacy and the 4th Amendment, but from a practical standpoint a search warrant is not a difficult hurdle to overcome.