Cross-posted from The Huffington Post. A federal warrant unsealed in May reveals how immigration authorities are using an invasive cell phone snooping tool, known as a “Stingray,” once confined to the battlefields of Iraq and Afghanistan. It is the first evidence of the device being used for immigration enforcement, and it highlights the need for greater transparency about how state and local police deploy similar tools.

As the Detroit News first reported, an Immigration and Customs Enforcement (ICE) agent obtained a warrant to deploy the Stingray, also called a “cell site simulator,” to find a 23-year-old undocumented restaurant worker from El Salvador accused of illegally re-entering the United States. The case is part of a dramatic uptick in immigration arrests during the first three months of the Trump administration.

Stingrays are fake cell phone towers about the size of a briefcase that force all phones in the area to connect to it – and by extension, law enforcement – instead of the phone company. They cause nearby phones to transmit unique identification numbers and can be used to accurately locate a particular device or even intercept its communications. Stingrays collect data from all phones in the area, not just the target phone, raising privacy concerns over what happens to the personal information that is collected incidentally.

Originally designed for military and intelligence agencies to fight terrorism overseas, Stingrays have proliferated domestically in the years since 9/11. Federal agencies, including ICE, have had them since at least 2008, but little was publicly known about why or how they were used. State and local police departments purchased them too, often through federal counter-terrorism grants. But they kept their existence shrouded in secrecy due to non-disclosure agreements with the FBI. That secrecy wound up jeopardizing thousands of prosecutions after word of the devices eventually came to light.

In 2015, both the Department of Justice and the Department of Homeland Security (which includes ICE) issued policies restricting the use of Stingrays. Agents must now obtain a judicial warrant based on probable cause and include important back-end privacy protections, like a requirement that non-responsive data be deleted. But those policies are not law and they do not apply to state and local law enforcement agencies using the devices on their own. That is a huge gap given that at least 68 state and local police departments around the country now own Stingrays, including the New York City Police Department (NYPD).

Unlike federal agencies, the NYPD has no public policy governing its use of Stingrays and it continues to fight requests for greater transparency despite having used the technology over 1,000 times since 2008. The department has stated that its practice is to obtain a “pen register order” prior to using the devices, a low bar to meet. It merely requires the police to show relevance to an ongoing investigation rather than probable cause for a search warrant. There is no indication that the NYPD deletes data scooped up from innocent bystanders and no information about what the Department does with it.

Detroit may mark the first time ICE has used a Stingray for targeted enforcement action, but it is unlikely to be the last. It is no coincidence that the case comes on the heels of Trump’s executive order on immigration. Under Trump’s new policy, just being in the country without permission is a crime sufficient to draw federal enforcement action – and the accompanying criminal search warrants. Consequently, sophisticated new surveillance technologies like Stingrays may now be used in low-level cases that would not have been pursued before Trump. It also raises the question of whether local agencies like the NYPD will be assisting.

Of course, New York is a “sanctuary city” that only complies with ICE “detainer” orders in cases involving certain “violent or serious felonies,” according to a 2014 city law. NYPD Commissioner James O’Neill has told officers in no uncertain terms that the “NYPD does not conduct civil immigration enforcement.” However, as in Detroit, illegal re-entry can provide a basis for criminal investigation and enforcement, at least federally. The NYPD maintains that it does not usually coordinate with ICE, but it does appear to regularly share information with ICE that facilities federal enforcement actions.

New Yorkers deserve to know more. They deserve to know how the NYPD is working with ICE and what information the Department is sharing. And they deserve to know how the NYPD is using new surveillance technologies like Stingrays.

A bill pending in the New York City Council would go a long way toward transparency on these questions. Dubbed the “Public Oversight of Surveillance Technology” (POST) Act, the law would require the NYPD to disclose basic information about the surveillance tools it uses, what happens to the data they collect, and whether the Department shares any of it with federal agencies like ICE.

If New York intends to be a model sanctuary city, then greater transparency is required. The NYPD should embrace this opportunity to build trust with community members, to inform the public about how the Department uses its surveillance tools and shares information with federal authorities. New Yorkers should not be left in the dark.

(Image: Flickr.com/ Marco Catini)