A group of four progressive lawmakers — Sens. Ed Markey (D-MA) and Jeff Merkley (D-OR) and Reps. Pramila Jayapal (D-WA) and Ayanna Pressley (D-MA) — sent letters to several federal agencies on Wednesday calling for an end to their use of Clearview AI’s controversial facial recognition system.

The letter was sent to the Departments of Justice, Defense, Homeland Security, and the Interior. All four agencies were identified in an August 2021 report from the General Accounting Office as using Clearview for “domestic law enforcement” purposes.

“Clearview AI’s technology could eliminate public anonymity in the United States,” the letter reads, describing the system as “capable of fundamentally dismantling Americans’ expectation that they can move, assemble, or simply appear in public without being identified.”

The same four lawmakers had previously introduced legislation that would bar federal law enforcement from using facial recognition technology entirely and add new restrictions for state and local police departments using the technology.

Clearview AI is unique among facial recognition vendors because of its internal database of identified faces, many of them scraped from Facebook, YouTube, and other social networks. The resulting system gives Clearview the power to identify many targets on sight but has made it the subject of ongoing legal actions in America, France, Australia, and other countries. Clearview CEO Hoan Ton-That has previously said more than 2,400 police agencies have entered into contracts with the company.

The letter adds to ongoing pressure on federal agencies to drop facial recognition systems entirely. On Monday, the director of the General Services Agency (GSA) told The Washington Post the agency is “committed to not deploying facial recognition… until rigorous review has given us confidence that we can do so equitably.” Still, other agencies are planning to expand their use of the technology once it is more adequately tested.