Aaron Graham was convicted of a series of armed robberies, based in part on over 7 months’ worth of historical cell site location information that was obtained by police without a warrant. He has petitioned the Supreme Court to grant a writ of certiorari. The Brennan Center - in conjunction with the Electronic Frontier Foundation, the Center for Democracy and Technology, the Constitution Project, and the National Coalition to Support Civil Freedoms - filed an amicus brief supporting his petition, and asking the Court to address whether the Fourth Amendment prohibits seizure and search of cell site location information without a warrant.
By way of background, a cell phone must connect to a cell tower in order to make a phone call or send or receive data. When it does, information about what tower the phone connects to is stored by the cell service provider. Given the ubiquity of cell phones in modern life, along with the growing density of cell towers, aggregated historical cell-site location information (CSLI) can provide an extremely detailed account of a person’s movements. In addition, third-party service providers may retain this data for years. Law enforcement agencies file tens of thousands of requests for CSLI data annually, often without a warrant.
Last year, a three-judge panel of the U.S. Court of Appeals for the Fourth Circuit held that the Fourth Amendment required police to obtain a search warrant to access this information. But when the case was reheard en banc (with the full court), that opinion was overturned on the basis of the “third party doctrine” - a legal principle dating from two 1970s cases, in which the Supreme Court held that in most circumstances, individuals do not have a reasonable expectation of privacy in information shared with a third party.
The brief urges the Court to hear the case, narrow the “third-party doctrine,” and recognize that long-term CSLI is so sensitive that the Fourth Amendment requires a warrant for police to access it.