The Independent reports that London’s Metropolitan Police was thought to have bought some towers for this purpose in 2009. Dubbed Stingrays, the Times alleged that the masts were activated in November and a report by Sky News today has confirmed they are now operating.
The “Stingrays” are IMSI catchers and are not actual phone masts. They mimic real ones so that phones perceive them as an actual tower and attempt to connect. The Stingray can then monitor all of the traffic to and from the phone.
The technique is known to be used throughout the world but this is the first time that its existence has been proven in the UK. Working with German security company GMSK Cryptophone over a three-week period, Sky News found over 20 operational Stingrays in London. Cryptophone’s CEO Bjoern Rupp said: “The abnormal events that Sky News had encountered can clearly be categorised as strong indicators for the presence of IMSI catchers in multiple locations.”
The Metropolitan Police refused to confirm or deny whether the force is using the masts, despite “repeated” Freedom of Information requests from Sky News. The UK’s most senior police officer and the commissioner of the Metropolitan, Bernard Hogan-Howe, told Sky News:
“We’re not going to talk about it, because the only people who benefit are the other side, and I see no reason in giving away that sort of thing. If people imagine that we’ve got the resources to do as much intrusion as they worry about, I would reassure them that it’s impossible.”
Because of the force’s refusal to directly comment on whether it is the operator of the towers, it is impossible to conclude exactly whose they are. Because IMSI catchers can be bought for around £1000 online, it is feasible that at least some of the Stingrays in London could be operated by criminals or even foreign governments.
The legality of their usage is currently unclear but their existence is likely to unsettle London residents. Because the towers are situated in Britain’s urban centre, each one could be collecting data from thousands of different phones every minute and sending it back for processing to whoever the Stingrays are being operated by.
