Federal immigration agents have used a powerful surveillance device called a “stingray” that spies on cellular phones 551 times nationwide during a recent three-year period, according to a government document released to Univision 41 Investiga.
Until now, little has been known about how often U.S. Immigrations and Customs Enforcement has used machines colloquially known as stingrays, which mimic legitimate corporate cell phone towers and hijack connections to triangulate the exact position of a person’s device.
“In total, ICE has deployed Cell Site Simulator technology 551 times from October 1, 2015 to September 30, 2018 in support of criminal investigations,” the agency disclosed in response to our formal request for the government’s records.
Three months ago, Univision 41 New York revealed how a federal judge allowed ICE to use a stingray in order to track a Mexican man who had illegally re-entered the United States. ICE officers arrested him at his girlfriend’s apartment in Brooklyn.
As part of our investigation, we filed an official request in September under the Freedom of Information Act seeking information on how the agency has employed a technology -- initially developed for national security -- against undocumented immigrants. The agency responded in a three-page letter earlier this month.
We shared this letter with three attorneys who are among the nation’s pre-imminent experts on stingrays. All were surprised by the response -- and lack of detail.
“It is news to me that they used this technology apparently more than 551 times over a three year period. That’s a lot,” said Nathan Freed Wessler, a senior attorney at the American Civil Liberties Union who regularly files records requests and lawsuits against the government to expose surveillance and privacy concerns.
“This is an unusual FOIA response, partly because they say at the end that they’re not even going to search for records,” Wessler said. “There’s no way that every single document related to this important technology can remain secret. That’s just not tenable.”
In its letter, ICE said it refuses to turn over any documents that would detail how or where the agency is using this spy tool -- or whether it is obtaining a judge’s permission to do so in every instance. The agency claimed an exemption to the federal public records law, citing a provision that allows holding back records that would either jeopardize sensitive law enforcement techniques or help criminals avoid law enforcement.
“How often was it done without a search warrant? How often was a judge reviewing this, and also how well did they understand what was being requested of them?” asked Jerome Greco, an attorney who supervises the digital forensics unit at the public defense organization Legal Aid Society.
It’s unclear from ICE’s response whether the agency is primarily using stingrays against undocumented immigrants or people suspected of violent crimes. That’s because the agency encompasses two very different law enforcement directorates. Enforcement and Removal Operations, ERO, is tasked with the mission traditionally attributed to ICE: deportations. But the other is Homeland Security Investigations, HSI, a law enforcement group that operates with little fanfare but is often behind the biggest busts against weapons traffickers, hackers, and child sex predators.
ICE’s letter hints that this second group, HSI, is the primary user of the technology. ERO is not mentioned once.
“While the use of cell-site simulators is becoming widely known through media exposure, the equipment that HSI currently operates, the manner in which it is utilized and the locations in which it is stored is still considered to be highly sensitive,” the letter stated.
The agency also appears to say that not all ICE field offices have stingrays at their disposal.
“At this time, not all HSI offices have the same equipment and, to confirm what locations have equipment to deploy would provide an advantage to criminal elements. If a criminal organization has confirmation that a device does or does not exist in a particular area, they may be sensible enough to change their method of communication or device use,” the letter said.
“It's really interesting to see how they are claiming a law enforcement exemption for not having to respond to your request, but still giving you a statement without any documents,” said Ángel Díaz, an attorney at the Brennan Center for Justice who studies the way surveillance technology chips away at civil rights.
“So you're just stuck with their account without any proof of what they're claiming, without any documentation,” he said.
Although investigative journalists have slowly revealed details about the existence and use of fake cell towers in recent years, much still remains a mystery. The Harris Corporation, based in Florida, is known to produce several versions of the device under the brand name "StingRay" -- a metal box roughly the size of a small guitar amplifier. It can fit in a car, and law enforcement is known to use it to identify the exact location of a suspect -- down to the building, apartment unit, and corner of the room. American law enforcement has been caught using stingrays on small, low-flying planes as well.
Such technology was initially justified as a national security tool, but journalists and lawyers are increasingly finding it used by local cops, like the NYPD, for routine law enforcement.
Initial fears that police have been secretly using stingrays to intercept calls and text messages have since been dialed back. When federal agents seeking judge-approved search warrants explain how they plan to use the technology, they describe a device that merely identifies a phone's location. But finding a specific phone requires duping all the devices in an area to connect to this fake cell tower, which alarms privacy advocates about the potential for mass surveillance. They say that undemocratic dragnets will occur if law enforcement does not immediately erase information incidentally collected from people who aren't the target of ongoing investigations.
ICE might be forced to turn over more documents revealing the use of stingrays. The ACLU filed a similar request in 2017 but said it has still not received a single document from ICE. Univision 41 Investiga's recent exposé about the case in Brooklyn prompted the ACLU to file a lawsuit against two federal agencies in December.