From automated license plate readers to drones to devices designed to identify gunshots, law enforcement agencies use a variety of tools to gather data. Dave Maass, senior investigative researcher with the digital privacy nonprofit Electronic Frontier Foundation, and Stanford students Craig Nelson and Shelby Perkins discuss which law enforcement agencies in the Bay Area use which technologies, and whether and how they are complying with a state law that requires them to publish their standards, policies, procedures and training materials online.