The ban comes after civil liberties groups highlighted what they described as faults in facial recognition algorithms after NIST found most facial recognition software was more likely to misidentify people of colour than white people. The Boston ban follows a ban imposed by San Francisco on the use of face recognition technology last year. The ban prevents any city employee using facial recognition or asking a third party to use the technology on its behalf. Boston's police department said it had not used the technology over what it called reliability fears, though it's clear the best systems are reasonably accurate in average working conditions. Critics also opposed the technology on the basis it might discourage citizens' rights to protest.

Boston has banned the use of facial surveillance technology in the city, becoming the second-largest community in the world to do so. The city council unanimously voted on Wednesday to ban the use of the technology and prohibit any city official from obtaining facial surveillance by asking for it through third parties. The measure will now go to Mayor Marty Walsh with a veto-proof majority. Walsh's office said he would review the ban. That move comes even as city officials say the technology isn't yet used by the Boston Police Department -- though the department could access those powers with a software upgrade.