WE’RE GOING TO HAVE TO LOOK MORE SERIOUSLY AT THE MOSAIC THEORY: License-plate readers let police collect millions of records on drivers.

The paperback-size device, installed on the outside of police cars, can log thousands of license plates in an eight-hour patrol shift. Katz-Lacabe said it had photographed his two cars on 112 occasions, including one image from 2009 that shows him and his daughters stepping out of his Toyota Prius in their driveway.

That photograph, Katz-Lacabe said, made him “frightened and concerned about the magnitude of police surveillance and data collection.” The single patrol car in San Leandro equipped with a plate reader had logged his car once a week on average, photographing his license plate and documenting the time and location.

At a rapid pace, and mostly hidden from the public, police agencies throughout California have been collecting millions of records on drivers and feeding them to intelligence fusion centers operated by local, state and federal law enforcement.

Prediction: It’ll be used more to stalk political enemies and law enforcement officers’ romantic interests than to solve crimes. More on the “mosaic theory” here.