On June 5, 2017, the Supreme Court of the United States granted certiorari in Carpenter v. United States, a case in which the court will assess and decide the extent of the Fourth Amendment’s protection against a warrantless search and seizure of cell-site-location information (CSLI), which includes the GPS coordinates of each cell tower and the dates and times any cell phone connects to it.
In Carpenter, the FBI obtained CSLI from wireless carriers linked to suspect Timothy Carpenter’s cell phone in an attempt to place him at the sites of several robberies. However, the CSLI obtained was not only for those dates and times of the known robberies, but also included months of records detailing every location from which Carpenter made a call—and all of this was obtained without a warrant.
Carpenter, who is represented by the American Civil Liberties Union (ACLU), argues that his Fourth Amendment rights were violated when the FBI obtained the CSLI without a warrant. However, the FBI relied on the “third-party doctrine,” a legal theory used by law enforcement to access personal data without having to demonstrate probable cause. This would allow access to certain information collected by private businesses for providing services to customers without constituting a “search.”