An investigation by Sky News has revealed that fake phone masts dotted around the UK are being used to track and collect your data without users ever knowing.
The report said that police and other investigation agencies use the technology to find out information about the residents of the country without seeking permission.
Known as IMSI catchers and Stingrays, the technology tricks phones into thinking they are logging onto a phone network, when in fact they are opening themselves up to covert tracking.
Eric King, deputy director of Privacy International, told Sky News: "With IMSI catchers, it's very difficult for them to be used in a targeted manner. In an urban space, thousands of people's mobile phones would be swept up in that dragnet. What they do with that data, we don't know.
"We know police have been using them for years, but this is the first time that it's been shown that they're being deployed in the UK."
Sky News used software made by GMSK Cryptophone to measure the activity in and around London. Over the course of three weeks, the software measured fake mast activity from Stingrays 20 times.
The Guardian has reported that the Metropolitan Police paid 143,455 for the fake masts in 2009, although the intensity of the scheme has only been picked up now.
Neither the National Crime Agency nor the Metropolitan Police would give a definite answer as to whether the tech was being used in the capital or not, with both saying if they revealed that type of information, the criminals and organisations were trying to stop would become wise to the tactics, which would defeat the object.
Bernard Hogan-Howe, the Metropolitan Police commissioner said: "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."
