US Patent and Trademark Office The StingRay surveillance tool allows police to track a cell phone's location down to the very room it's in.
A Stingray works by mimicking a cellphone tower. Authorities drive around with the device sending out signals, and all mobile devices in the vicinity are forced to connect to it. This means that police could have access to phone calls, text messages, and other private data.
The device is controversial because of the scattershot way it operates - it often captures data from nearby devices, not just the intended target.
But the tool, which was originally created for overseas warfare, is powerful. And if it's used is a situation like catching a terrorist, there is certainly an argument that it is justified. What's less easy to defend is the Stingray's use in minor incidents of local crime.
But it's certainly being used in that manner by law enforcement.
An article from Capital News shed light on the extent of its use by local law enforcement in Maryland, and some of the uses are surprising. One in particular jumps out.
Capital News points to one instance where a pizza shop's employee in Annapolis was robbed of 15 chicken wings and three sub sandwiches while out on a delivery run. The value of the stolen items was $56.77. The police got a court order to use a Stingray, but didn't end up catching the robber.
"It's supposed to be used for terrorism," Janine Meckler, the Baltimore public defender, told Capital News. "It's not being used for the purpose for which it's being designed." And Meckler should know. Stingrays have been used to surveil Baltimore residents more than 4,300 times since 2007, according to a report last year by the Baltimore Sun.
Additional reporting by Cale Guthrie Weissman.