The Justice Department is using “dirtbox” surveillance devices mounted on Cessna aircraft to scoop up bulk data from cellphones as part of a secret US spy program. The DOJ program, which is run by the Technical Operations Group of the US Marshals Service, has been fully functional since 2007, according to sources cited by the Wall Street Journal .

Flights equipped with the “dirtboxes,” which mimic cell towers of large communications firms and trick cellphones into reporting their unique registration information, operate from at least five metropolitan-area airports, with a flying range covering most of the US population, according to the Journal .

The airborne surveillance devices, which are produced by Digital Receiver Technology Inc. (DRT), allow investigators to collect data from thousands of cellphones in a single flight. In addition to tracking locations, the devices can jam signals and retrieve data such as text messages and photos. The airborne devices have significantly increased the volume of cell phone information accessible to the US government, according to the sources cited by the Journal.

DRT promotes the “dirt boxes” as having the strongest signal, capable of inducing all phones within range to send their unique registration information, including phones secured with encryption technology. “DRT has developed a device that emulates a cellular base station to attract cellphones for a registration process even when they are not in use,” Boeing noted in papers filed with the US Department of Commerce.

Once an individual’s cellphone has been identified, the technology can pinpoint its location to within about 10 feet, down to a specific room in a building.

The majority of data collected in this way comes from phones of users “who aren’t criminal suspects,” sources cited by the Journal acknowledged. A Justice Department official on Friday refused to confirm or deny the program, claiming that to do so would allow criminals to better evade law enforcement.

So-called “stingray” devices have been in use by local law enforcement agencies to track cell phones for some time. Law enforcement officials “are borrowing cell phone tracking devices known as “stingrays” from the U.S. Marshals Service—and police are deliberately concealing the use of stingrays in court documents submitted to judges in criminal investigations,” according to a report by the American Civil Liberties Union (ACLU).

Law enforcement agencies “hide behind the sham cloak of the U.S. Marshals’ office to keep the information about stingray use out of court files—and beyond even a court’s custody and reach,” the ACLU found.

An email written by a Sarasota Police Department sergeant indicates that there are concerted efforts by law enforcement to conceal their use of dragnet surveillance technologies against the general public.

“In the past, and at the request of the U.S. Marshalls [ sic ], the investigative means utilized to locate the suspect have not been revealed so that we may continue to utilize this technology without the knowledge of the criminal element. In reports or depositions we simply refer to the assistance as ‘received information from a confidential source regarding the location of the suspect.’ To date this has not been challenged,” the police officer wrote.

These latest revelations make clear that the DOJ and the US Marshals Service follows the NSA’s principle of collecting as much data as possible on as many people as possible, regardless of their suspected involvement in a crime.