The U.S. Department of Justice released a policy that will require its law enforcement components to obtain a search warrant before using devices (commonly known as “Stingrays”) that simulate cell-phone towers to track the location of cell-phone devices.  This voluntary policy change by DoJ follows on the heels of decisions by the U.S. Court of Appeals for the Fourth Circuit (U.S. v. Graham) and the U.S. District Court for the Northern District of California (In Re: Application for Telephone Information Needed for a Criminal Investigation) that law enforcement must get a warrant in order to obtain historical cell-site location data from cell-phone carriers.  Notably, the DoJ policy does not apply directly to state and local law enforcement.  However, it may affect state and locals’ use of Stingrays to the extent they rely on federal assistance in deploying the equipment.