The nation’s first big-city ban on the use of facial-recognition technology by municipal agencies and local law enforcement passed Tuesday in San Francisco, signaling the next front in the debate over data privacy. Voting 8-1, supervisors in the tech hub made an exception for federally regulated facilities, like the airport. Oakland is considering a similar measure, and San Francisco Assemblyman Phil Ting has authored a more limited statewide version. SF police actually don’t use facial recognition. But privacy advocates say other law enforcement agencies do (San Jose, San Diego, California Department of Justice), that the technology can violate privacy, and that it can be inaccurate, especially with subjects who are not white men.