Identity theft in Tennessee is covered under section 39-14-150 of the Tennesssee Penal law. It states:
(1) A person commits the offense of identity theft who knowingly obtains, possesses, buys, or uses, the personal identifying information of another:
(A) With the intent to commit any unlawful act including, but not limited to, obtaining or attempting to obtain credit, goods, services or medical information in the name of such other person; and
(B) (i) Without the consent of such other person; or
(ii) Without the lawful authority to obtain, possess, buy or use that identifying information.
It's a class D felony in your state, punishable by anywhere from 2 to 12 years if prison. That said, if your friend were interested in a plea bargain rather than going to trial on the deal, if he has no previous felony history, he would likely be looking at nothing worse than probation and restitution, meaning he'd have to pay back any money that he got through the use of the cards.