Police use Stingray devices to spoof cell phone towers like this one in Sudbury, Massachusetts.

Story highlights

The secret devices are used by law enforcement to mimic a cellphone tower, tricking phones to connect through the Stingray, instead

The Justice Department had to date largely declined to comment on use of the devices, citing national security and not wanting to telegraph U.S. capabilities to enemies

Washington CNN  — 

The Justice Department on Thursday issued new guidance for how federal law enforcement can use controversial technology that dupes cellphones to collect evidence – placing substantially more requirements on what has been a shadowy policing technique.

At issue are cell-site simulators, also referred to as “Stingrays,” one type of such device. The secret devices are used by law enforcement to mimic a cellphone tower, tricking phones to connect through the Stingray, instead. That allows law enforcement to capture data from the phones, including location information and call traffic. The Justice Department says the technology is programmed to collect no more than that.

The technology has become highly controversial. A report from The Wall Street Journal last year revealed that the feds flew airplanes over the U.S. carrying Stingrays to scoop up call information. And a judge in March detailed a deal between the FBI and local sheriff’s office to drop cases rather than reveal any information about the use of Stingrays to gather evidence.

The Justice Department had to date largely declined to comment on use of the devices, citing national security and not wanting to telegraph U.S. capabilities to enemies.

But U.S. law enforcement point to the capture