These people left me 2 recorded announcements that they are the IRS and have a pending lawsuit. I called them. First indication of fraud...Indian guy answers and says his name is Jason Smith.
Yes, mess with them! Call back from a different phone that does not broadcast your name and number on Caller ID. Just say that you received their call and wanted to resolve the issue, but do not give your name. Chances are you will not be asked for it. Once the scammer tells you how much you owe, tell him you want to be sure this concerns you so ask him, "What's my name? What's my Social Security number?" When he fumbles around, call him enough names to make a sailor blush, then hang up.