Eight democratic lawmakers sent a letter to Amazon CEO Jeff Bezos on Thursday reiterating their concern about Amazon’s facial recognition technology, Rekognition, and the company’s decision to make it available for the use of law enforcement agencies.

The lawmakers acknowledged that while facial recognition may at some point in the future serve as a useful tool for law enforcement officials, the technology was not fully developed, and has “significant accuracy issues.”

According to the lawmakers, the product places disproportionate burdens on communities of color, and could stifle Americans’ willingness to exercise their First Amendment rights in public.

The lawmakers expressed concern regarding troubling information from pilot programs involving Amazon’s Rekognition technology. They also said recent revelations show that Amazon is actively marketing the defective product to law enforcement entities, including U.S. Immigration and Customs Enforcement.

According to reports, law enforcement officials have started using cameras to collect raw video footage of bystanders, transferring the data to Amazon servers for facial recognition analysis.

The lawmakers accused Amazon of failing to provide sufficient answers despite numerous requests to that effect. They renewed their call for information and requested written responses to a series of questions aimed at ensuring that Amazon’s Rekognition software is accurate, not biased, protects privacy rights of innocent Americans and other measures to reduce abuse of the software.

Signatories to the letter include including Sen. Edward Markey and Reps. John Lewis and Judy Chu.