FBI on trial for warrantless Stingray mobile spying
In an Arizona court case, the FBI has been forced to defend its use of a phony cellphone tower dubbed Stingray that it's using to analyse mobile phone traffic and identify suspects.
The Stingray system came to light in the case of Daniel David Rigmaiden, who stands accused of reaping millions of dollars from filing phony tax returns on the basis of identity theft. The FBI were able to catch Rigmaiden in 2008 by tracking down the 3G card he was using as a modem, but it didn't disclose that the Stingray had been used in this process without a warrant.
The Stingray system uses a dummy mobile base station that mimics a standard cellphone tower, and can locate cellphones by their International Mobile Station Equipment Identity numbers, and monitor calls. This works even if the phone isn't in use, since the Stingray can provoke a response from any device that's switched on.