More than 20 “intrusive” fake mobile phone towers that eavesdrop on public conversations have been found active in the UK, the first time the technology has been detected in the country.
The IMSI catchers, also known as Stingrays, have been found to be operating in London, but the Metropolitan Police have refused to say who is controlling them or what is being done with the information they are gathering.
IMSI stands for International Mobile Subscriber Identity – a unique number that identifies users on their phone network.
The controversial surveillance technology, used by police forces around the world, is supposedly for catching criminals’ communicating by intercepting information on its way to the network.
It tricks mobile phones into thinking the Stingrays are phone masts, so that handsets connect to the tower and all the data flowing through them is collected – but the masts are unable to distinguish between criminals and everyone else.