Viruses, Trojan horses, worms, time bombs, adware, spyware, keystroke tracking tools, spoofing, snooping, sniffers -- these are some of the most popular examples of malicious code and techniques that modern organizations find themselves fighting. Couple this seemingly unabated tide of new releases and new forms of harmful software with human threats like crackers, thieves, industrial espionage contractors, and your own disgruntled or ill-intentioned employees, and what do you get? You get a complex cocktail of potential security headaches. How big a headache? The computer security industry is estimated to be in the billion-dollar range -- a big headache if measured by the size of the "preventive medicine" market.