How would you feel if someone could track your every move, at any time, without your knowledge? Depending on where you live, law enforcement officials can place GPS tracking devices on your vehicle, without your permission and without a warrant.

"If you're putting GPS tracking on somebody who's a known felon, that a little different than your average citizen," said Taylor Paine.

It sounds like something out of a spy movie...secretly putting a tracking device on your car in the dead of night...but according to a federal ruling in California, law enforcement officers can do just that, and they no longer need a warrant.

"They just did it, law enforcement just went out and did it," said lawyer Lane Thibodeaux.

With apps like four square, you have control over people knowing where you are, like letting friends know you're headed to the pool, or still stuck at work, but when law enforcement steps in, you may not have that choice.

"There are some very good investigative purposes for those devices," said College Station police officer Rhonda Seaton.

There's a variety of reasons why law enforcement want to track your goings on.

Professor Phillip Lyons, with the Sam Houston State University's College of Criminal Justice said, "{They follow} suspects in cases, witnesses, even victims in some instances and these tracking devices make that process much simpler than traditional surveillance."

It's a relatively new technology, but College Station police uses them.

"{We} put it on property, have it tracked after it was stolen...you could put it on a vehicle," officer Rhonda Seaton said. "We are going to go to great lengths not to invade somebody's privacy...however, we do want to catch the bad guy."

Some people say this violates a person's reasonable expectation of privacy.

Taylor Paine said, "It kind of sounds like that might be a little bit excessive."

"The ends don't justify the means in Texas, or anywhere else," lawyer Lane Thibodeaux agreed.

Others say its necessary.

"I think the whole world changed after 9-11...there's a new set of rules governing everything...I'm glad to see it," said State Representative Fred Brown.

Now police are getting more done with less manpower, time and money.

"In the case of Texas, for example, a search warrant is required under these circumstances even though in many circuit courts of appeal...that requirement is not there," said Professor Lyons.

Its also not the only to find you.

Criminal lawyer Lane Thibodeaux said, "Under the right circumstances, law enforcements are able to track your movements via or through your GPS tracking device in your cell phone."

With splits among the state and federal courts, experts agree if technology keeps evolving, the laws will have to change too. The Bryan police department said their "specialized units will not comment on any tactics they use in their line of police work."