A retired San Francisco schoolteacher is accusing the city of running a “Big Brother” surveillance dragnet that illegally tracks everyday drivers. Michael Moore, a retired public school teacher, filed a federal class-action lawsuit Monday alleging sweeping Fourth Amendment violations. Moore says the city’s Flock license-plate reader system unlawfully monitors his movements as he drives to stores, his sons’ schools and family gatherings — all without a warrant or probable cause. San Francisco has installed roughly 450 to nearly 500 Flock cameras along major roadways, making it “functionally impossible” to drive anywhere in the city without having your license plate photographed,...