http://triblive.com/mobile/5533722-96/fbi-agency-data
"Don't assume it's the cellphone company's fault the next time you drop a call.The denial of service might be the result of a “StingRay” interceptor mounted on an FBI agent's car. The gadget works by mimicking a cellular telephone tower, fooling phones and wireless computers into connecting with its strong signal instead of the nearest antennae of the large telecommunications companies.The high-tech tool is handy when agents need to throw a wide electronic dragnet to capture all the cellular traffic in a neighborhood, especially to uncover criminals who use prepaid “burner” phones to evade police monitoring. But the cell tower simulator intercepts untold numbers of innocent calls, including the extensions dialed, the length of conversations and the caller's location."