And it's not just other passengers overhearing that you need to be worried about. I personally don't show a drivers license at the checkpoint because the TDC then knows my address AND that I'm leaving town and for where (at least the first destination). Now, you might argue that they aren't smart enough to remember addresses, but do you want to take that chance? Besides - it's best to not miss a chance to let them know they are more criminal than you are.

I'd certainly never have a chat with any TSA employee about my travel plans. Who knows what kind of shady background they have? Who knows if they're going to take some kind of criminal interest in you?