
(credit: Josh Koonce)
On Wednesday, the Maryland Court of Special Appeals published a legal opinion finding that state police must not only obtain a warrant before deploying a cell-site simulator, but are required to also fully explain to the court what exactly the device does and how it is used.
As Ars has long reported, cell-site simulators—known colloquially as stingrays, can be used to determine a mobile phone’s location by spoofing a cell tower. In some cases, stingrays can intercept calls and text messages. Once deployed, the devices intercept data from a target phone along with information from other phones within the vicinity. At times, police have falsely claimed the use of a confidential informant when they have actually deployed these particularly sweeping and intrusive surveillance tools.
In recent years, stingray use has come under increasing scrutiny, with several states including California, Washington, Virginia, Minnesota, and Utah now mandating a warrant be issued for their use. Last year, the Department of Homeland Security and the Department of Justice also imposed new policies that require a warrant for stingray use in most cases.







