We use facial recognition technology to unlock our cell phones, doors, and find friends on social media apps. But there's a real fear about how tech companies and government is recording our faces and tracking our movements. That’s one reason why the San Francisco Board of Supervisors voted Tuesday to ban city agencies, including the police department, from using this type of technology. The ordinance is part of a larger policy package that is supposed to give the city control over what surveillance technology gets used. San Francisco could become the first city in the nation to ban facial recognition software if the ordinance passes its final vote later. Guest: Rachael Myrow, KQED’s acting Silicon Valley Bureau Chief