The U.S. Marshal service is using specially-equipped airplanes to pick up information about the location of Americans’ cell phones, according to a report by the Wall Street Journal. The flights are primarily used in an attempt to pinpoint the location of fugitives and drug dealers by getting their cell phones to talk with a device that fakes the signal that a cell tower would put out. However, the Journal notes that the surveillance program also collects information of those who are not suspects.
Here’s how WSJ reporter Devlin Barrett describes the program:
Planes are equipped with devices—some known as “dirtboxes” to law-enforcement officials because of the initials of the Boeing Co. unit that produces them—which mimic cell towers of large telecommunications firms and trick cellphones into reporting their unique registration information.
The technology in the two-foot-square device enables investigators to scoop data from tens of thousands of cellphones in a single flight, collecting their identifying information and general location, these people said.
Once a cell phone picks up the signal, it sends back its identifying information, which allows Marshals to figure out where people are. It’s possible for the officers to get similar information by requesting it from cell phone companies, but actually flying a fake tower over a suspect makes it easier to pinpoint that person’s location.
At the center of the program is hardware built by Digital Receiver Technology, a company Boeing purchased in 2008. Digital Receiver Technology makes signal capture equipment, including the devices that are used by the Marshals.
Flights are usually conducted to seek out multiple fugitives in the same area. Because the devices emulate a cell tower, they can pick up thousands or tens of thousands of signals from other citizens who aren’t being targeted by the Marshals. It’s not clear what the Marshals’ data retention policy is, though if they hold onto the data, it would allow them to track people beyond those who were originally targeted.
This is another story in a long line of law enforcement agencies using cell phone surveillance. The FBI and other groups have used car-mounted devices known as “Stingrays” to track cell phones as well.
Spokespeople for the U.S. Department of Justice and Boeing were not immediately available for comment on this report. Read the full report on the program, which the ACLU calls “inexcusable” — here.