The TeleZapper is a product from a company called Privacy Technologies. This device is plugged into your phone line and is supposed to delete your number from telemarketer databases. It works by emitting a tone that tell the a computer dialer that your number has been disconnected. The TeleZapper can detect a computer dialed call when you or your answering machine picks up the call. When the telemarketer receives this disconnection tone, their computer should remove you from their database so they don't waste their time dialing disconnected numbers. Eventually less calls should be made to your number.