In a rare move against the advance of license plate readers, Louisiana Governor Bobby Jindal (R) has vetoed a plan to acquire the scanners in the Bayou State. It had previously passed both houses of the Louisiana legislature overwhelmingly.

Many law enforcement agencies nationwide use these specialized cameras to scan cars and compare them at incredible speeds to a "hot list" of stolen or wanted vehicles. In some cases, that data is kept for weeks, months, or even years.

In a signing statement Friday, Jindal wrote:

Senate Bill No. 250 would authorize the use of automatic license plate reader camera surveillance programs in various parishes throughout the state. The personal information captured by these cameras, which includes a person’s vehicle location, would be retained in a central database and accessible to not only participating law enforcement agencies but other specified private entities for a period of time regardless of whether or not the system detects that a person is in violation of vehicle insurance requirements. Camera programs such as these that make private information readily available beyond the scope of law enforcement, pose a fundamental risk to personal privacy and create large pools of information belonging to law abiding citizens that unfortunately can be extremely vulnerable to theft or misuse. For these reasons, I have vetoed Senate Bill No. 250 and hereby return it to the Senate.

The bill, as written, would have limited the retention period to just 60 days.

Earlier this year, Ars obtained 4.6 million LPR records collected by the police in Oakland, Calif. over four years and learned that just 0.16 percent of those reads were "hits." We discovered that such data is incredibly revelatory. We were able to find the city block where a member of the city council lives using nothing but the database, a related data visualization tool, and his license plate number.