Senate Judiciary Committee Chairman Patrick Leahy (D-Vt.) and Ranking Member Chuck Grassley (R-Iowa) have asked Attorney General Eric Holder and Secretary of Homeland Security Jeh Johnson several questions about the government’s use of cell site simulators or “Stingray” devices to track cell phones. According to the letter, the Senators previously asked FBI Director James Comey about the FBI’s use of cell site simulators and, after two briefings with the Senators, the FBI announced a new policy that it would obtain search warrants before using the devices, subject to certain exceptions. The new letter raises questions about the broader use of cell site simulators by other law enforcement agencies and their impact on the privacy of innocent individuals. EPIC filled a lawsuit under the Freedom of Information Act in 2012, seeking information about the FBI’s use of cell site simulators and, in particular, what legal process the agency required before deploying the technology. As a result of EPIC’s lawsuit, more than 4,000 pages of partially-redacted FBI records were released to the public. For more information, see EPIC v. FBI - Stingray / Cell Site Simulator.