If you get a phone call from "the IRS" demanding that you pay your back taxes in the next two hours or there will be police and/or a federal agent on your doorstep to arrest you, simply inform them that *you* are a federal agent. Or if you think you can't pull that off. that there is one sitting across the room from you, and would they like to speak to him? FBI/CIA/NSA/NCIS -- doesn't really matter which alphabet soup agency you choose. They hang up in microseconds!