The American Civil Liberties Union of New Mexico has sued the city of Albuquerque, seeking records by the city’s police department about its use of stingrays, also known as cell-site simulators.

In May 2017, the ACLU of New Mexico filed a public records request to the Albuquerque Police Department (which has been under federal monitoring for years), seeking a slew of information about stingrays. The requested info included confirmation on whether the police had stingrays, "policies and procedures," and contracts with the Harris Corporation, among other materials. Albuquerque denied many of these requests, citing a state law that allows some public records to be withheld on the grounds that they reveal "confidential sources, methods." So, last week, the ACLU of New Mexico sued.

As Ars has been reporting for years, stingrays are used by law enforcement to determine a mobile phone's location by spoofing a cell tower. In some cases, stingrays can intercept calls and text messages. Once deployed, the devices intercept data from a target phone along with information from other phones within the vicinity. At times, police have falsely claimed the use of a confidential informant when they have actually deployed these particularly sweeping and intrusive surveillance tools. Often, they are used to locate criminal suspects.

In 2015, the Department of Justice and the Department of Homeland Security said a new policy would require that agents obtain a warrant before using a stingray. But this policy does not apply to local or state-level law enforcement unless a city ordinance or state law mandates it. (Some states, like California for example, require a warrant when police use a stingray.)

"These devices are incredibly invasive and the government isn’t being transparent about how they are being used," ACLU of New Mexico Executive Director Peter Simonson said in a statement. "If the APD is using Stingrays to snoop into people’s private information, the public has a right to know. We also need to ensure that protections are in place to prevent these powerful tools from being misused or abused."

A lawyer for the police department did not immediately respond to Ars’ request for comment.

APD spokeswoman Celina Espinoza told the Albuquerque Journal in a statement that the department “follows legal standards with the use of any technology," but did not answer further questions.