TAMPA, Florida - August 23, 2010 - When Martin O'Malley became Maryland's governor in 2007, one of his first moves was to double the number of cameras used to spy on cars. The cameras, stationed at tollbooths and parking garages and mounted on police cars, scan license plate numbers and instantly match them with a database for tracking stolen cars.

The sort of Big Brother criticism one might expect of a program like this never materialized in a substantial way. There's a good reason: The rate of vehicle theft in Maryland has plummeted to its lowest level since the state began collecting data in 1975. This month, O'Malley pledged to add 100 more license plate cameras.

A very different story is unfolding in neighboring Pennsylvania. When Governor Ed Rendell recently proposed using the tag readers to crack down on a separate problem - uninsured and unregistered drivers - the plan sparked waves of protest. A key difference is that Rendell has been playing up the idea of using the cameras to raise revenue from fining drivers. Rendell says Pennsylvania stands to pocket $115 million a year.

Using tag readers explicitly as a revenue-raising tool seems to have made many Pennsylvanians uncomfortable. The auto insurance industry has come out against the plan, saying the technology is not accurate enough to avoid levying erroneous fines on their insurance-carrying customers.

Meanwhile, the civil liberties argument has surfaced more in Pennsylvania than it ever did in Maryland. "It is very Orwellian to think about putting cameras up all over the state and have them randomly or not randomly catch license plate photos," says state Senator John Gordnor, who sits on the Senate Transportation Committee.

States are playing an important part in rolling out the technology, helping police departments pay for the cameras, which can cost as much as $20,000 per unit. In Maryland, O'Malley is using federal grants and some existing state funds to pay the $2 million cost of his tag reader expansion.

"Having surveillance technology makes people feel uncomfortable," said Zachery Heiten, a legal director with the MCLU. "It's wrong to treat everybody as if they're a criminal suspect."