20. What is scanning?

Scanning is dialing a large number of telephone numbers in the hope of
finding interesting carriers (computers) or tones.
Scanning can be done by hand, although dialing several thousand telephone
numbers by hand is extremely boring and takes a long time.
Much better is to use a scanning program, sometimes called a war dialer or
a demon dialer. Currently, the best war dialer available to PC-DOS users is
ToneLoc from Minor Threat and Mucho Maas. ToneLoc can be ftp'd from
ftp.paranoia.com /pub/toneloc/.
A war dialer will dial a range of numbers and log what it finds at each
number. You can then only dial up the numbers that the war dialer marked as
carriers or tones.

21. Is scanning illegal?

Excerpt from: 2600, Spring 1990, Page 27:
-BQ-
In some places, scanning has been made illegal. It would be hard, though,
for someone to file a complaint against you for scanning since the whole
purpose is to call every number once and only once. It's not likely to be
thought of as harassment by anyone who gets a single phone call from a
scanning computer. Some central offices have been known to react strangely
when people start scanning. Sometimes you're unable to get a dialtone for
hours after you start scanning. But there is no uniform policy. The best
thing to do is to first find out if you've got some crazy law saying you
can't do it. If, as is likely, there is no such law, the only way to find
out what happens is to give it a try.
-EQ-
It should be noted that a law making scanning illegal was recently passed
in Colorado Springs, CO. It is now illegal to place a call in Colorado
Springs without the intent to communicate.