NORTH TEXAS (CBSDFW.COM) – A new trend from auto insurers may reveal more about your driving than you want.

You may have seen the ads showing a plug-in device that auto insurers promise will help lower rates for good drivers.

Progressive and other insurance companies are using devices that keep track of your good driving habits, but may also show the bad.

“I think there’s some very complex privacy problems associated with this,” Dallas attorney Peter Vogel, with Gardere Wynne Sewell, said.

Vogel teaches a course on internet privacy at Southern Methodist University said the data people are voluntarily giving their insurance company could be used against them in a court of law.

“Individuals do not necessarily realize that they’re giving up their right of privacy associated with where they go and what their speed is.”

Vogel says the data that’s voluntarily being given up could be used as evidence, for example, in a divorce case.

“Then you’re surprised to find out that in a divorce proceeding that one spouse finds out the other spouse was cheating on them or something, because they have these records that are available from the insurance company.”

Vogel says the laws on the use of GPS data have not really made it to the courts, but it’s related to the same kind of privacy issues as people who reveal personal information on social networks.