By Katherine Kwong – Edited by Mengyi Wang
According to a report in the Wall Street Journal, the U.S. Marshals Service has been using airborne “dirtboxes” to collect data on mobile phones. The program, designed for criminal suspect surveillance, is accused of also collecting cell phone data on many Americans who are not suspected of any crime.
"Dirtboxes” - named after the acronym for their manufacturer, Digital Recovery Technology Inc. (now owned by Boeing Co.) – induce cell phones to connect to them by imitating cell phone towers. A dirtbox sends cell phones signals that indicate that it is the strongest cell tower available, causing cell phones to connect automatically to it. Doing so allows the dirtbox to collect the International Mobile Subscriber Numbers (IMSI) of all devices in range. The data collected from the cell phones can be used to identify and locate individuals to a relatively small area. The U.S. Marshals Service has placed the devices on Cessna airplanes leaving from five different airports, allowing the program to cover a large proportion of the U.S. population. Each flight has the potential to collect data from “tens of thousands” of Americans, according to the Wall Street Journal article.
It is unclear how much the devices might disrupt the normal operations of cell phone networks. Dirtboxes can briefly interrupt phone calls, but authorities say they have sought to minimize harmful impacts by taking steps to ensure 911 calls are not interrupted. Verizon told the Wall Street Journal they were unaware of the program, while other major carriers declined to comment. In a follow-up article in the Wall Street Journal, the Federal Communications Commission (“FCC”), which is responsible for licensing and regulating cell phone services, said, “We were not aware of this activity.” Frederick Joyce, a communications law attorney, questioned whether the program constituted “harmful interference” with licensed cell phone transmissions.
In addition to questions of communications law, a number of commentators expressed concerns about the legality of the program from a civil liberties standpoint. "There are some serious and troubling legal questions about this program," Hanni Fakhoury, a Staff Attorney for the Electronic Frontier Foundation, told Gizmodo. "It's important to note this is very different from the government getting this information from a phone company. In the last few months, many state courts and legislatures have required law enforcement get a probable cause search warrant to use these devices. The US Marshals should explain how this program works and what kind of court authorization, if any, they're obtaining to fly planes with 'dirtboxes.'"
Similarly, Brian Owsley, a law professor at Indiana Tech and a former U.S. magistrate judge, told Ars Technica, "Regarding using planes as cell towers, that is problematic in my opinion. It strikes me as analogous to the use of Stingrays. Therefore, I think the government would need to obtain a search warrant based on probable cause consistent with the Fourth Amendment[.]"
Some commentary, including that of IEEE Spectrum, compared the surveillance program to controversial data gathering efforts previously conducted by the National Security Agency (“NSA”).
Politicians have also voiced concerns about the program. Senator Edward Markey of Massachusetts told the Wall Street Journal, "The collection of American's personal information raises significant legal and privacy concerns, particularly for innocent consumers.'' Senator Al Franken of Minnesota, chairman of the Privacy, Technology, and the Law subcommittee, said, "While law-enforcement agents need to be able to track down and catch dangerous suspects, that should not come at the expense of innocent Americans' privacy."
In the Wall Street Journal follow-up, defenders of the program argue that it is an important tool for law enforcement. A government official also stated that the purpose of the program was “not to conduct domestic surveillance or intelligence gathering,” but solely for law enforcement. The official particularly rebutted the comparison to the NSA’s previous telephone records collection, saying that the U.S. Marshal Service does not retain the data collected from non-suspects.