By Diane Cooke
An International Mobile Subscriber Identity-catcher, or IMSI-catcher, is a telephone eavesdropping device used for intercepting mobile phone traffic and tracking location data of mobile phone users.
The hardware tricks mobile phone handsets across an area of several miles into connecting to them by impersonating cellphone towers, and can be used to pinpoint phone owners’ locations or intercept phone calls and text messages.
Back in 2016, The Guardian reported that seven police forces across the UK were using the technology.
The Metropolitan police were previously known to have purchased IMSI technology. However, documents obtained by the Bristol Cable, a citizen’s media cooperative, indicated that at least six other police forces had bought the same hardware, also referred to as CCDC (covert communications data capture).
As well as the Met, other forces understood to be using it include West Mercia, Warwickshire, West Midlands, Staffordshire, Avon and Somerset, and South Yorkshire.
Police have refused to acknowledge their acquisition of this technology or discuss how they use it, claiming that any disclosures could assist criminals and terrorists.
Matthew Rice, an advocacy officer at the campaign group Privacy International, told The Guardian: “IMSI catchers, by their very nature, operate indiscriminately, gathering information from all individuals in the particular operating area. This collateral intrusion into the private lives of many innocent individuals is deeply concerning in any context let alone one that is, almost deliberately, opaque.”
The Daily Maverick says the implications of such devices are enormous. In the wrong hands, they can be used to eliminate political rivals and curb a free press by targeting investigative journalists.
What is even more frightening is that in recent years, IMSI-catcher technology – which was previously only within the grasp of governments – is now accessible to hackers and researchers who have been able to successfully build their own grabbing devices.
IMSI-catchers, or grabbers, have been around since 1996, with German and Israeli companies pioneering the early technologies. The first publicly known IMSI-catcher was made by German electronics manufacturer Rohde & Schwarz. Subsequent manufacturers have marketed the devices as “anti-terror equipment” with many law enforcement and intelligence agencies across the world making use of the devices – most notably and controversially perhaps is the use of the Stingray phone tracker by US police.