In 2016, police officers in Baltimore used new technology to scan the faces of protesters who filled the city’s streets following the death in custody of Freddie Gray, a 25-year-old black man. Among those whose most recognizable features may have been documented was Rep. Elijah E. Cummings, the Democratic chairman of the House Oversight and Reform Committee.

Three years later, Cummings is still angry such surveillance was conducted without a warrant or reason to believe that he — or any other protester, for that matter — had done anything illegal. Now he’s putting the full weight of his committee’s jurisdiction behind a push to ban facial recognition technology until Congress can pass comprehensive legislation to govern its use.

The rise of software that can recognize and identify faces has long been the stuff of science fiction, but now it’s widely used by private companies and law enforcement agencies despite a complete lack of standards or privacy protections for individuals. Whether facial recognition technology violates someone’s constitutional rights has yet to be decided in court.

Democrats and Republicans both say that if its use continues unchecked, the technology poses a range of threats to everyday Americans, whether through illegal surveillance or misidentification. Because industry-wide best practices haven’t been established, critics say faulty software can find its way into the hands of those who don’t know how to properly use it, potentially with serious consequences.

“Our faces may well be the final frontier of privacy,” Joy Buolamwini, a research assistant at the Massachusetts Institute of Technology and founder of the Algorithmic Justice League, told the committee at a hearing last week.