Surveillance cameras, like the one here in Boston, are used throughout Massachusetts. The state now regulates how police use facial recognition technology. Massachusetts lawmakers passed one of the first state-wide restrictions of facial recognition as part of a sweeping police reform law. The new law sets limits on how police use the technology in criminal investigations. It's one of the first attempts to find middle ground when regulating this technology, but not all privacy advocates agree that regulation is the right step. Democratic state Sen. Sonia Chang-Díaz was one of the leaders behind this push for criminal justice reform.