It's possible information about where you drive is being recorded and saved in secret, national databases.  Investigators say it's a valuable tool for finding criminals, and even people who don't pay their parking tickets or car payments but privacy advocates want rules and regulations.

By simply passing vehicles on a highway, a city street or in a parking lot, car-mounted cameras can record up to 3,500 license plates a minute.  A computer then saves and tags the plate picture with the date, time and location it was taken.

“Most people don't know that this is happening,” said car owner Mike Katz-Lacabe.

Until Katz-Lacabe requested pictures from his local police department in California, he had no idea officers had stored 100 plate photos of his family's cars around town over a two-year period.  He was surprised to see himself in a photo and in another, his children in his driveway.

“I was shocked. It’s very powerful information,” he said.

So who's out there scanning plates?  Private companies, car repossession agents and according to a report from George Mason University, more than 37 percent of large law enforcement agencies across the country.

So where does that information go?  Some police departments keep their own plate databases.  But some law enforcement agencies and repo firms send it to private companies like MV TRAC.

MV TRAC is a leading plate recognition system seller and it maintains a massive national license plate photo database.

"It’s perfectly legal. It’s not infringing on anyone's rights,” said Scott Jackson, with MV TRAC.

It is perfectly legal to shoot and store video shot in public.  But national privacy advocates want this plate storing practice to yield, and want to know how long photos are being kept. how they are being used and who has access to them across the country.

“There are no rules that govern it. There’s no overall governing structure. There's no law that would impact how the different municipalities and states would implement this, and therefore the potential for misuse or unintended use is extraordinarily high,” said Attorney Mary Ellen Callahan, Former Privacy Officer with the Department of Homeland Security.

An International Association of Chiefs of Police survey shows some agencies keep the plate information indefinitely, while others delete data after a few months.  The Association says it's critical to crime fighting and police keep the info secure.

“We don't know of a single instance where automated license plate recognition data has been misused or abused,” said David Roberts, Senior Program Manager with the International Association of Police Chiefs.

MV TRAC says it keeps its plate data indefinitely and only police and car repossession companies that have passed an in-depth background check can access its database.  It's system alerts a user when a "hot listed" or "wanted" plate is discovered.

“There's no real concern for privacy unless you've done something wrong. if you’ve done something wrong, you're a murderer, if you are a child abductor if you've committed a crime or if you haven't made your car payments in a long time, then that's a permissible purpose as well," said Jackson.

Katz-Lacabe says even though he's no criminal, he's still not comfortable with his daily activities being caught on camera and stored.

“That sort of thing frightens me,” he said.

MV TRAC says it does not sell the plate data to members of the public or marketing firms.