I wrote about this a while back in a thread started by Hugo I believe. This essentially allows them to drive around and a camera scans the plates of cars it sees. The location time etc are then logged into a database painting a picture of day to day movement of individual law abiding citizens.
http://news.yahoo.com/ark-police-photograph-license-plates-store-data-180420324.htmlIt also allows authorities to monitor where average citizens might be at any particular time. That bothers some residents, as well as groups that oppose public intrusions into individual privacy. The groups are becoming more alarmed about license plate tracking as a growing number of police departments acquire the technology.
Though authorities in Washington, D.C., London and Chicago conduct extensive electronic surveillance of public areas to detect security threats or deter gang crime, "Today, increasingly, even towns without stoplights have license plate readers," said Catherine Crump, a New York-based staff attorney with the American Civil Liberties Union.
In Little Rock, even some city officials wonder about keeping data on drivers' movements.
"It bothered me particularly if someone wasn't guilty of a crime or didn't have any active warrants or hadn't committed a crime," city director Ken Richardson said.