Using a PC and a phone line, a skilled person could shut off electricity 
to whole regions of the country, or cripple police and fire service by 
disabling 911 service. According to the commission's report, an 
estimated 17 million people in the U.S. have the skills to carry out 
such attacks.

[17 Million?! There are some 60 million *internet users* WORLD-WIDE
by some estimates. This figure is ridiculous.]

"The public-switched network carries 90 percent of communications for 
systems like railroads, financial data, electricity, natural gas and the 
telephone service," said Terry Hawkins, director of the Nonproliferation 
and International Security division of the Los Alamos National 
Laboratory. The New Mexico lab is one of the primary centers where 
research is being conducted into ways to "harden" the U.S. 
infrastructure to protect it from tampering by people who either have 
political motives, or who are simply determined to crack computer 
systems for perverse satisfaction.