The cell-phone hackers of the past, who electronically jimmied phones for the thrill and free phone service, have graduated to Web site hacking. Today, there are an estimated 440 hacker bulletin boards, 1,900 Web sites purveying hacking tips and tools, and 30 hackers publications like "Phrack" and "2600: The Hacker Quarterly." There are readily available software programs for hacking tactics like "war dialing," "sniffing" and "fingering" — all used to exploit security weaknesses in computer systems.

WheelGroup will now try to gain access by avoiding the Internet and attacking XYZ's individual computers. It will use a method called war-dialing. Consulting the phone number on the business card of an XYZ employee, the hackers assume (correctly) that computer modems at the company will use the same area code and three-digit prefix. Waddell downloads a free program from the Internet called ToneLoc, written by hackers named Minor Threat and Mucho Maas. It comes with a manual that explains how to automatically call thousands of phone numbers within a specific range.

Hacking sessions often stretched into the early morning hours. He would start by checking lists of computer phone numbers collected by his computer the night before through an automatic process called "war dialing." That's the brute force approach to hacking, when the computer runs through the night, methodically dialing every number in a telephone exchange. It records the number whenever it hits a "carrier tone" signaling a computer is on the other end.