# Telezapper **URL:** \ **Category:** Factual Questions\ **Created:** [November 30, 2001, 11:15pm UTC](https://boards.straightdope.com/t/telezapper/96214 "2001-11-30T23:15:21Z")\ **Posts on this page:** 2\ **Page:** 1
**Author:** ![Roadfood](https://avatars.discourse-cdn.com/v4/letter/r/9fc348/32.png) [@Roadfood](https://boards.straightdope.com/u/Roadfood)\ **Post date:** [November 30, 2001, 11:15pm UTC](https://boards.straightdope.com/t/telezapper/96214/1 "2001-11-30T23:15:21Z")
I saw a commercial for the Telezapper last night, and checked out their website today ([http://www.telezapper.com](http://www.telezapper.com)). It’s a small device that you attach to your phone line. The claim is that it will automatically stop telemarketers by sending a signal to the telemarketers’ auto-dialer telling it that your line is out of service. So is this for real? Does it work? What is this magic tone that tells an auto-dialer that the phone is disconnected, even though it was just answered (the telezapper sends its magic signal when you (or your answering machine) answer the phone)? ---
**Author:** ![bibliophage](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/bibliophage/32/7615_2.png) [@bibliophage](https://boards.straightdope.com/u/bibliophage)\ **Post date:** [December 1, 2001, 4:31am UTC](https://boards.straightdope.com/t/telezapper/96214/2 "2001-12-01T04:31:09Z")
This question has been asked several times in recent months, so I will close this thread and direct any remaining unanswered questions to one of the earlier threads: [http://boards.straightdope.com/sdmb/showthread.php?threadid=92161](http://boards.straightdope.com/sdmb/showthread.php?threadid=92161) bibliophage moderator GQ