Reps. Keith Ellison, D-Minn., and Emanuel Cleaver, D-Mo., sent a letter to Amazon CEO Jeff Bezos on Friday morning, demanding answers about how the tech giant’s facial recognition technology is being used by law enforcement agencies around the country.

The letter, provided to The Intercept ahead of its public release, lists a total of 12 requests for information regarding Amazon’s facial recognition service, branded as “Rekognition,” including the names of any law enforcement or government agencies that use the system and data on how the service could enable, or itself engage in, discrimination, including racial and gender bias.

“The disproportionally high arrest rates for members of the black community make the use of facial recognition technology by law enforcement problematic,” the letter reads, “because it could serve to reinforce this trend.”

According to an Ellison aide, the letter is an attempt to enact at least a baseline level of congressional oversight for the tech giant — an attempt that comes less than two months after congressional hearings that tried to do the same for Facebook.

Amazon came under fire earlier this week after the American Civil Liberties Union and its affiliates, as well as 35 other civil liberties organizations, released a public letter expressing concerns about how Amazon markets its technology to law enforcement agencies. The ACLU letter coincided with the release of a trove of documents, which the organization obtained through public records requests and after a six-month investigation, that shed light on the company’s relationship and correspondence with law enforcement agencies in Oregon and Florida.

Right now, it’s known that at least two governmental agencies — the Washington County Sheriff’s Office in Oregon and Orlando Police Department in Florida — use Rekognition software. Among the demands in Ellison and Cleaver’s letter is a list of other law enforcement customers that currently use the software, a list of private companies that develop tools that use Rekognition software for use by law enforcement agencies, and the results of any independent auditing that Amazon Web Services may have conducted to identify error or bias in the software. Importantly, the congressmen are also asking for any “terms of use, policies, or other restrictions” the company places on the use of its technology by customers, including police departments. The letter asks for a response to its inquiries from Bezos by June 20.

“I worry about the threat it presents for the targeting of black and brown communities in particular.”

Amazon released its Rekognition technology in November 2016, through its cloud services platform Amazon Web Services, and soon after started marketing the software specifically to law enforcement agencies like those in Washington County and Orlando. The company says the software can identify people in real time by searching image databases, and also has a “person tracking” feature that “makes investigation and monitoring of individuals easy and accurate.”

“I worry about [facial recognition technology’s] potential for abuse as a tool for warrantless surveillance,” Ellison said in a statement to The Intercept, “and the threat it presents for over-policing and targeting of black and brown communities in particular.”

The emails obtained by the ACLU also reveal that an Amazon employee attempted to set up a meeting between someone at the Washington County Sheriff’s Office and a representative from an Amazon customer called Federal Signal that manufactures body cameras. What’s more, in its marketing materials, Amazon boasts that Utility Associates, a manufacturer of body-worn cameras, is one of the users of the software. On the Rekognition website, Utility Chief Technology Officer Simon Araya brags that using Rekognition in conjunction with body-worn camera technology “dramatically decreases the time needed to act and provides a valuable situational awareness tool for law enforcement” — in other words, officers could engage in real-time surveillance in the course of their duties.

Cleaver has long called for the widespread use of body-worn cameras by law enforcement officers, and in 2015 successfully pushed to allocate $22.5 million in federal funding for that purpose, as part of an omnibus spending bill. Ellison and Cleaver write in their letter that this kind of collaboration could transform police body-worn cameras “from tools designed for officer accountability into surveillance devices aimed at the public.”