Body-worn IMSI catcher takes covert phone snooping to next level

IMSI catchers, known more commonly by the biggest selling trade name, "Stingray" devices," are fake cell-phone towers that police use to capture nearby cell traffic and fool it into running calls through a police-operated device small enough to deploy in a squad car. Now they're big enough to wear as clothing.

ACLU's Chris Soghoian described the feds' deployment of Stingray-type technology (that's a trade name, the technical term is "IMSI catcher") worn by law enforcement as a vest at the conference on Location Tracking and Biometrics, an event Grits attended at the Yale Law School, thanks to with reader support) earlier this year, which was the first I'd heard of it. Now we learn more about the body-worn tech in a new report from Ars Technica ("The body worn 'IMSI catcher' for all your covert snooping needs," Sept. 1), which opened:

Recently leaked brochures advertising next generation spy devices give outsiders a glimpse into the high-tech world of government surveillance. And one of the most tantalizing of the must-have gizmos available from a company called GammaGroup is a body-worn device that surreptitiously captures the unique identifier used by cell phones.

"The unit is optimized for short range covert operation, designed to allow users to get close to Target(s) to maximize the changes of only catching the Target(s') identities and minimal unwanted collateral," one of the marketing pamphlets boasts. "The solution can be used as a standalone device or integrated into wider data-gathering and geo-tracking systems."

At just 41 x 33 x 18 centimeters, the device is small enough to fit under a shirt. It needs from one to 90 seconds to capture the international mobile subscriber identity (IMSI) or international mobile equipment identity (IMEI) of the person being tracked. It works on all GSM-based networks regardless of country and is fully operational even when functioning in a moving vehicle. The same brochure advertises several other varieties of IMSI catchers, including some that work in a totable briefcase and one that receives signals from a covert vehicle roof bar antenna. The James Bond spying tools are sold to government agencies and law enforcement organizations.

Soghoian described experiments by the feds having agents with body-worn IMSI vests walking through crowds at political rallies and recording the ID of every cell phone that pinged,. That gave them a lot of baseline data about who was at the event, how to target their phone if need be in the future, etc., Combined with the rise of license plate readers, continued warrantless access to historic location data (at least for now), a national facial recognition database about to come online, and near ubiquitous surveillance in most public places, the potential uses and misuses of such more-or-less unregulated police technology boggles the mind.

Read the whole thing.