Now Playing: 08-17-12 Marketplace Tech Report

The American Civil Liberties Union is filing information requests with nearly 500 police departments in 38 states having to do with License Plate Reader cameras, or LPRs. Apparently, tens of thousands of them are being used around the country. The cameras help police spot cars that may be wanted, but according to the ACLU, the problem lies in the fact that the cameras store people's license plate numbers for a long time, and there's not that much known about how the technology is actually being deployed.