When residents of a ritzy West L.A. neighborhood experienced an increase in burglaries last year, they decided to invest in technology to fight the problem. The neighborhood association in Cheviot Hills — a community of million-dollar homes sandwiched between the 10 Freeway and Century City — raised more than $200,000 to purchase scores of controversial, high-tech cameras that scan license plates. The automated plate readers, as they are known, enable authorities to track when vehicles of interest pass through certain intersections. The devices can also be mounted on police cars, allowing officers to sweep up troves of license plate data...