Editing TeleZapper (section)

== Limitations of the TeleZapper ==
A predictive dialer merely checks for three conditions:
*A SIT signal, as described above,
*a short response, like "hello", in which case it puts the called person through to a salesperson, and
*a long response, such as an answering machine message, in which case it hangs up and re-queues the number to call back later or leaves a sales message.

Some telemarketing firms have turned off the SIT tone detector altogether in response to the TeleZapper trick, rendering it wholly ineffective.

Another limitation is that the device does not work well with [[voice mail]] systems.  This is because voice mail reroutes the call from a physical line to the voice mail service without the phone ever picking up.