Whether it's teenagers hacking into your system (known as "ankle-biters"), disgruntled employees or cyber-criminals, having your computer system breached is a serious and costly matter.

Most hackers and computer security specialists agree that every system can be hacked, it's just a matter of time and resources. When the Department of Defense reported a recent hacking incident of its computer sites, they said that the hacking represented "the most organized and systematic attack the Pentagon has seen to date."

One of the national newspapers reported that when one of the main perpetrators, a high school student from Cloverdale, California (known among his fellow hackers as "Makaveli") was interviewed a few days later, he explained the rush hackers get from breaking into secure systems... "It's power, dude, you know, power."

All of us remember the movie "War Games," where a high school student used his computer to breach a defense project computer system, almost setting off World War Three in the process. Not long after the movie was produced, the first real life college student hacking was reported when the military and intelligence computers were breached and shut down. It was a wake-up call to corporations and governmental agencies alike.

In response to the attack, the federal government set up the Computer Emergency Response Team (CERT) at Carnegie Mellon University. CERT is designed to provide advice and assistance when government systems are penetrated. Each large business needs a similar defense plan. Reacting after the breach has occurred is too late, you need to develop a plan and identify the consultants and outside advisors long before a disaster occurs.

Computer Security Institute conducted a survey of large US corporations, government agencies, and universities. Sixty-four percent of the 520 which responded to the survey reported computer break-ins over the last year. An increase of 16% over the prior year. There was also an increase in the number of break-ins originating from the Internet.

Many hackers and cyber-criminals are posing as temporary staff in order to learn more about the systems and their vulnerability. A recent case was reported where the hacker was employed as a janitor by the company, in order to take advantage of the reduced security on site. The computer systems were well protected to outside intruders, but internal security methods were lax.

Lax internal security is often enables disgruntled employees to erase, modify or sabotage important files, such as for research and development, trade contacts and customer lists, legal files and personnel records. An employee, seeking to build a sexual harassment case against her employer, used remailer technology to send herself an e-mail under the guise of her supervisor. Luckily, before the case progressed very far, her deception and the true identify of the e-mailer was discovered, and the woman was charged with perjury. Tighter internal security could have prevented her using the remailer, and saved everyone lots of time and money.