In a landmark 5-4 decision, the United States Supreme Court held that the government conducts a search under the Fourth Amendment and therefore, absent exigent circumstances, needs a warrant supported by probable cause when obtaining cell-site location information (i.e., records of the cell towers to which mobile devices connect). The majority reached that conclusion based on the determination that such location records are subject to a reasonable expectation of privacy that continues to apply even though the location records are disclosed to the cell phone user’s wireless carrier, a third party.
On Monday, the Supreme Court granted certiorari in Carpenter v. United States, a Sixth Circuit case that provides the Court with the opportunity to clarify whether individuals have a reasonable expectation of privacy in location data shared with electronic communications service providers. Specifically, the Court will consider whether the Fourth Amendment requires law enforcement to obtain a warrant for the search and seizure of wireless carriers’ cell phone data that reveals the cell phone user’s location over the course of several months; or whether such location information falls within the long-recognized “third-party doctrine” exception to Fourth Amendment protections. A definitive Supreme Court holding on these issues could clarify presently muddled case law surrounding cell-site tracking data and perhaps inform judicial interpretations of privacy torts and other issues related to the collection, use, and sharing of location data.