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Stop robot callers with a tone

Computers & Mobile
Stop robot callers with a tone


Aparently there’s a U.S. Special Information Tone signal for a dead phone line, and robot callers (telemarketers, debt collectors, etc.) listen for it, then remove the “dead lines” from their lists. Record it at the beginning of your answering machine messages to make (some) robots stop calling you! [via] Link.

(Photo by Flickr user scriptingnews)

20 thoughts on “Stop robot callers with a tone

  1. james says:

    is that a standard headset adapted to the mini plug a phone uses? anyone got a link for that?

  2. Becky Stern says:

    follow the photo credit link for more information.

  3. Ryan says:

    Um, or just submit your phone number to If you get a telemarketing call you get after that you can get them heavily fined, so they don’t.

    I signed up years ago and haven’t gotten a single telemarketing call since.

  4. the steven says:

    I seem to remember buying a device, I believe it was called a “phone zapper”. I plugged it in and havent gotten a telemarketer call since.

  5. Sporkinum says:

    Does that still work? I bought a device to do that about 10 years ago. It runs off the phone line voltage.

  6. John says:

    Thinkgeek Retro Phone Handset

    Theres the link to that handset attached to the phone. Its sweet.

    I got a spy remote from the same site that lets me control the tv at the local bar. They wonder how the tv ends up on Comedy Central every time I’m there.

  7. tyler durden says:

    This may be especially useful in an election year!

  8. MadScott says:

    The “Phone Zapper” and similar devices simply respond to calls with the dead-line tone. The unintended consequence of putting this on your answering machine is that people you actually want to talk to may think your line’s out of order and hang up.

  9. James says:

    @MadScott: Your friends and family will only hang up if they don’t wait long enough to hear you say “Hello” or your outgoing answering machine message.

  10. Phone User says:

    Some high schools have an automated phone system that calls parents when their student is absent. Playing hooky just got easier.

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Becky Stern is a Content Creator at Autodesk/Instructables, and part time faculty at New York’s School of Visual Arts Products of Design grad program. Making and sharing are her two biggest passions, and she's created hundreds of free online DIY tutorials and videos, mostly about technology and its intersection with crafts. Find her @bekathwia on YouTube/Twitter/Instagram.

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