We use an MP3 file with the At&T boo booo beep non working number tone. The Robo Dialer recognizes this tone and automatically removes your number and sends the removed number to all the other robo dialer list's as a bad number and BINGO no more robo or political calls.
Keeps calling my unlisted number, even after 9 at night. I think I will turn my fax machine on. There should be a law to stop bottom feeders like this.