... San Francisco's board of supervisors voted to ban the use of facial-recognition technology by the city's police and other agencies. Oakland and Berkeley are also considering bans, as is the city of Somerville, Mass... Two new reports by Clare Garvie, a researcher who studies facial recognition at Georgetown Law... uncovered municipal contracts indicating that law enforcement agencies in Chicago, Detroit and several other cities are moving quickly, and with little public notice, to install... "real time" facial recognition systems... researchers discovered that [Detroit] signed a $1 million deal with DataWorks Plus, a facial recognition vendor, for software that allows for continuous screening of hundreds of private and public cameras set up around the city... [Ms. Garvie said] "Face recognition gives law enforcement a unique ability... to conduct biometric surveillance — the ability to see not just what is happening on the ground but who is doing it... We've never been able to take mass fingerprint scans of a group of people in secret... Now we can with face scans."

... The most troubling thing about all of this is that there are almost no rules governing its [facial recognition's] use. [P]eople are being arrested, charged and convicted based on similar practices in face searches. And because there are no mandates about what defendants and their attorneys must be told about these searches, the police are allowed to act with impunity... None of this is to say that facial recognition should be banned forever. The technology may have some legitimate uses.