FBI gags state and local police on capabilities of cellphone spy gear

The Federal Bureau of Investigation requires state and local police to keep quiet about the capabilities of a controversial type of surveillance gear that allows law enforcement to eavesdrop on cellphone calls and track individual people based on the signals emitted by their mobile devices, according to a bureau document released recently under a Freedom of Information Act request.

The December 2012 document is a heavily redacted letter between the FBI and police in Tacoma (WA) as the local department sought to acquire an IMSI catcher, sometimes described as a “fake cellphone tower” because it tricks individual phones into routing their calls and other data through the surveillance equipment. The Takoma police were buying gear produced by Harris Corp., a Florida-based company that makes the StingRay and other IMSI catchers used by law enforcement agencies across the country. The FBI letter, which was not classified but was designated as "law enforcement sensitive," told the Tacoma police chief that the Federal Communications Commission authorizes the sale of such surveillance equipment to state and local police departments on the condition that they first sign an FBI “non-disclosure agreement.”