If you've seen the hit TV show "Person of Interest", no doubt you've seen some of the latest technolgy that cities and police departments are using for surveillance.

Some of that same technology is being used here in the valley.

Installed on top of two police cars in Cathedral City, sit small box-like cameras called "automatic license plate readers".

"They are a great investigative tool and a great crime fighting tool," said Cathedral City Police Captain Chuck Robinson. 

The license plate readers are small high-speed cameras, which automatically take pictures of hundreds of license plates in a single minute.  

With every scan, a license plate number is recorded, along with the date, time, and location of the vehicle.

If the number scanned matches up with that of a vehicle previously entered into a Department of Justice database, the police officer receives an alert, and the wanted car can then be tracked down.

"As an investigative tool, it is even greater of a tool for us, because if we have a plate we are looking for, and don't know where it is at, associated with a particular crime, we can actually enter that plate in.  We can drive around.  If we find it, it gives us an opportunity to do further investigation," said Robinson.

Captain Robinson says the LPRs have already been used to recover several stolen cars in Cathedral City, which averages about one stolen car a day.

Robinson says the benefits of what the devices offer outweigh the downsides of the technology, which for some people, include concerns about privacy.

The devices are being used to track the whereabouts and driving patterns of potentially every citizen on the road, including those obeying the law.

Also, the collected data can be stored indefinitely, as is the case in Cathedral City.  

The American Civil Liberties Union is among the groups and individuals who express concerns about the use of the license plate readers, saying there aren't enough privacy protections in place.

Just one example they point to is state police in Virginia using the LPRs to record data on drivers gathered at political events.

Citizen's we talked on the street expressed a range of opinions about the technology.

"It is not an invasion of privacy, because its their job to protect you," said Cathedral City resident "Daniella".

"I feel like it is too much surveillance, and they are watching us too much," said Christopher Maldanado. 

The police captain acknowledges that while there is a chance for the technology to be abused, he says that law abiding citizens have "nothing to worry about".

Investigators using the license plate readers for legitimate purposes would be using the vast amounts of data collected, "only because a suspect has given them a reason to do so", said Robinson.  

"We live in a society where video is everywhere.  Your vehicles have GPS built into them.  It is s just a different time than 15 to 20 years ago.  These are common things as part of our society," said Robinson.

Captain Robinson adds the license plate readers allow the officers in his department to do "more with less", which is especially important for the agency which is operating with 18 fewer sworn officers on the streets because of budget issues.

Other police departments around the valley using the LPRs include La Quinta, Indian Wells, Palm Desert and Coachella.