In Detroit, driving at night north up Woodward Avenue, a long, wide boulevard, one’s eye is caught by emerald green lights, perched on the topmost corners of gas station signs, laundromats, corner stores, peep shows, groceries, and churches. They blink quickly, three times in a row. Their green makes for strange beacons, at first eerie, then comforting, not a warning, but an invitation. The green lights are part of Project Green Light Detroit, an initiative undertaken by the Detroit Police Department to create safer businesses through a “public-private community partnership.” Business owners buy real-time cameras which generate feeds that run continuously ...