The U.S. government is making progress on developing a surveillance system that can pair computers with video cameras to scan crowds and automatically identify people by their faces, according to an article from the Boston Globe.

The Department of Homeland Security recently tested a crowd-scanning project called the Biometric Optical Surveillance System (BOSS) after two years of government-financed development. The researchers’ significant advanced alarm privacy advocates, who say that now is the time for the government to establish oversight rules and limits on how it will someday be used, the article says.

There have been attempts at building such a system that would help match faces in a crowd with those on a watch list, including terrorism suspects, fugitives or card cheats, but the technical hurdles involved with scanning crowds from a distance were too challenging.