Three license plate readers that Menlo Park (near San Fransisco) police began using this summer captured images of more than 250,000 plates between July 1 and Oct. 1, according to a police staff report.
Out of all those images, however, only one could be tracked to a crime. Police recovered a stolen car and arrested the thief.
The readers, which cost a total of $57,914, are mounted on the roofs of two marked patrol cars and one unmarked vehicle used by detectives. Each has four high-speed cameras that take pictures of license plates in front of, behind and alongside police cars. The collected data is then uploaded to a server managed by the Northern California Regional Intelligence Center, part of the Department of Homeland Security.
Would it be out of line to suppose that this data, what cars were where, and when, though obviously in public... is useful to the dept of homeland defense for only one reason. Tracking each and every car photographed, it's movements, and habits.
Police Commander David Bertini said the license plate readers' role in locating stolen vehicles is "almost secondary" to its value as a "deterrent to bad guys" and an investigative tool for solving crimes.
Mayor Ray Mueller said "Technology such as this one, while it may be OK with safeguards today, in the future, it may not be. As the government's ability to aggregate information and apply complex algorithms and artificial intelligence to track people's lives increases, the balancing test of whether or not that technology is infringing upon the public's right to privacy will change."
found on http://www.mercurynews.com/peninsula/ci_26990245/cameras-that-read-263-430-license-plates-menlo