During a cellphone call, the cellphone interacts with its mobile carrier, allowing the carrier to track that phone’s approximate location, also known as cell-site location information or “CSLI.” CSLI is saved on the carrier’s computer system. Prosecutors can obtain this CSLI, often without a warrant, to place defendants at crime scenes by tracing movements of the cell phone and its user through both public and private places.

In August 2015, a divided three-judge panel of the United States Court of Appeals for the Fourth Circuit, in Richmond (covering Maryland, North and South Carolina, Virginia, and West Virginia), ruled the government’s procurement of cellphone location data from mobile carriers was an unreasonable search under the Fourth Amendment because “[e]xamination of a person’s historical CSLI can enable the government to trace the movements of the cell phone … and thereby discover the private activities and personal habits of the user” and “cell phone users have an objectively reasonable expectation of privacy in this information. Its inspection by the government, therefore, requires a warrant, unless an established exception to the warrant requirement applies.” United States v. Graham, No. 12-4659 (4th Cir. Aug. 5, 2015).

The Fourth Circuit’s panel holding created a split among the Circuit Courts. The Eleventh Circuit (covering Alabama, Florida, and Georgia) and the Fifth Circuit (covering Texas, Mississippi, and Louisiana) have held that historical CSLI is not protected by the Fourth Amendment.

However, on October 28, 2015, the Fourth Circuit granted the government’s petition for rehearing en banc, before all judges of the court, in Graham, vacating the panel decision and eliminating for now the apparent circuit split and any immediate need for Supreme Court resolution . The increasing interest among the Circuit Courts in possible Fourth Amendment protection of electronic information reflects an increasing realization that computer search issues are important, difficult and in need of careful attention.

The U.S. Supreme Court likely will need to address the increasingly important issue of Fourth Amendment protection for private individual and business information stored electronically with a third party carrier.