Future Tense

FBI Files Unlock History Behind Clandestine Cellphone Tracking Tool

FBI documents show how easy it is for them to monitor your movements using cellphones

Photo by Oli Scarff/Getty Images

It was described recently by one rights group as a “secretive new surveillance tool.” But documents just released by the FBI suggest that a clandestine cellphone tracking device known as the “Stingray” has been deployed across the United States for almost two decades—despite questions over its legality.

Stingrays, as I’ve reported here before, are portable surveillance gadgets that can trick phones within a specific area into hopping onto a fake network. The feds call them “cell-site simulators” or “digital analyzers,” and they are sometimes also described as “IMSI catchers.” The FBI says it uses them to target criminals and help track the movements of suspects in real time, not to intercept communications. But because Stingrays by design collaterally gather data from innocent bystanders’ phones and can interrupt phone users’ service, critics say they may violate a federal communications law.

A fresh trove of FBI files on cell tracking, some marked “secret,” was published this week by the Electronic Privacy Information Center. They shed light on how, far from being a “new” tool used by the authorities to track down targets, Stingray-style technology has been in the hands of the feds since about 1995 (at least). During that time, local and state law enforcement agencies have also been able to borrow the spy equipment in “exceptional circumstances,” thanks to an order approved by former FBI Director Louis Freeh.

EPIC, a civil liberties group, obtained the documents through ongoing Freedom of Information Act litigation that it is pursuing in order to get the feds to hand over some 25,000 pages of documents that relate to Stingray tools, about 6,000 of which are classified. The FBI has been drip-releasing the documents monthly, and there have been a couple of interesting nuggets in the batches so far—like a disclosure that the FBI has a manual called “cell tracking for dummies” and details hinting that the feds are well aware the use of Stingrays is in shaky legal territory.

The latest release, amounting to some 300 selectively redacted pages, not only suggests that sophisticated cellphone spy gear has been widely deployed since the mid-‘90s. It reveals that the FBI conducted training sessions on cell tracking techniques in 2007 and around the same time was operating an internal “secret” website with the purpose of sharing information and interactive media about “effective tools” for surveillance. There are also some previously classified emails between FBI agents that show the feds joking about using the spy gear. “Are you smart enough to turn the knobs by yourself?” one agent asks a colleague.

On a more serious note, EPIC attorney Alan Butler told me he believes the release raises further legal questions about the technology. It shows that the bureau has been classifying the use of “cellsite simulator” as a “pen register device,” following guidance issued by the Department of Justice. “Pen register” is a term used to describe a type of surveillance that does not usually require a search warrant because it records only metadata—the who, where, and when of a communication but not the content. However, Butler pointed out, a June 2012 ruling in the Southern District of Texas found that Stingrays should require a warrant, with the judge concluding that “the government has not provided any support that the pen register statute applies to stingray equipment.”

Stingrays have garnered attention since a 2011 Arizona court case in which one agent admitted in an affidavit that the tool collaterally swept up data on “innocent, non-target devices” (U.S. v. Rigmaiden). The government eventually conceded in this case that the “tracking operation was a Fourth Amendment search and seizure,” meaning it required a warrant. But given that the Justice Department has continued to claim that cellphone users have no reasonable expectation of privacy over their location data, it may take a Supreme Court judgement to settle the Stingray issue countrywide.

In a statement emailed in response to questions about Stingray technology, FBI spokesman Christopher Allen told me that its use of “any investigative tool” is required to be in compliance with the Constitution, U.S. laws, internal DOJ guidelines, and is subject to internal and external oversight. He added that the bureau “strives to protect our country and its people using every available tool, with utmost respect for the rule of law and our cherished right to privacy.” 

“Location information is a vital component of law enforcement investigations,” Allen wrote. “During the course of FBI investigations and as permitted by controlling legal authority, the FBI may use a variety of tools and technology, including cell phone location technology.”