SURVEILLANCE: UK Cops Using Fake Mobile Phone Tower to Intercept Calls, Shut Off Phones. “The portable device, which is the size of a suitcase, pretends to be a legitimate cell phone tower that emits a signal to dupe thousands of mobile phones in a targeted area. Authorities can then intercept SMS messages, phone calls and phone data, such as unique IMSI and IMEI identity codes that allow authorities to track phone users’ movements in real-time, without having to request location data from a mobile phone carrier. In the case of intercepted communications, it is not clear whether the network works as a blackhole where intercepted messages go to die, or whether it works as a proper man-in-the-middle attack, by which the fake tower forwards the data to a real tower to provide uninterrupted service for the user. In addition to intercepting calls and messages, the system can be used to effectively cut off phone communication, such as in a war zone where phones might be used as a trigger for an explosive device, or for crowd control during demonstrations and riots where participants use phones to organize.”