Rep. Jason Chaffetz has introduced a bill in the U.S. Congress that would prohibit government agencies from using cell-site simulators (or stingrays) without a warrant in most circumstances. The Cell-Site Simulator Act of 2015 would also explicitly exclude stingrays from the pen register statute currently used by law enforcement to conduct stingray operations with less than probable cause. The government would still be able to conduct warrantless stingray operations under the Foreign Intelligence Surveillance Act or in emergencies. An EPIC FOIA lawsuit in 2012 revealed that the FBI was using stingrays without a warrant. EPIC has also filed amicus briefs arguing that cell phone location data is protected by the Fourth Amendment.