There are an estimated 35,000 hackers in the U. S. and their community is growing by an estimated 10 percent annually. They are not isolated individuals, slaving away in a vacuum; hackers have established formal operations within every metropolitan city in North America.

And, they are organized. They gather on the first Tuesday of every month for a nationwide "2600" meeting, named after one of their leading trade magazines. Four additional meetings are held throughout the U. S., normally in Texas (Ho Ho Con), St. Louis, Missouri (Summer Con), San Francisco (Fall Con) and Las Vegas, Nevada (World Con).

Hackers communicate via compromised Internet gateways, long-distance calls stolen from corporate victims and through about 1,300 underground bulletin boards across the U. S. This infrastructure collects and disburses a constant flow of stolen calling-card information, corporate voice-mail-access data, compromised PBX DISA-port numbers, hackable modems, cloned cellular telephones and stolen cellular-phone ID's.

Hackers use computer programs called "war dialers," to scan or dial thousands of telephone numbers quickly. The programs can also identify which called numbers are PBX/voicemail ports, modems and computer-access lines. This allows hackers to call back and use focused attack strategies.

The threat to U. S. businesses also has recently taken a new direction, due to hackers' growing numbers and maturity. Security investigations have confirmed that known hackers are employed within Fortune 500 firms, which know nothing about the individuals' prior activities. The risk to U. S. businesses is clear: What will happen when one of these hacker's employment is terminated? Will the individual destroy or damage the company's voice/data networks, release vital information about these networks to other hackers, or plant the seeds of future destruction in a company's systems? Time will tell.