An organization by the name of Sky News uncovered at least 20 rogue telephone masts operating in London.
Known as stingrays or cell-site simulators, the towers mimic mobile phone masts and trick cellphones into logging-on and granting access to the owner’s calls and data.
According to theantimedia.org:
The sophisticated surveillance technology listens to mobile phone conversations without the owner’s permission by leading the handsets to believe they are genuine mobile phone towers. As with all controversial surveillance techniques, they are allegedly used by security agencies to target the communications of criminals. Like other methods of data harvesting, stingrays monitor thousands of phones at a time and sweep information from all devices in the targeted area — yes, that means yours.
Read the full article here.