"China's IT space is really one of the most malware-ridden in the world," Fitzsimmons said, attributing the problem to widespread use of pirated software and a lack of attention to security management, such as applying software patches that fix vulnerabilities.

"In terms of platforms that people could attack in China, or subvert to attack something else, there's quite a bit out there," he said.

Apart from hackers looking to use the Olympic Games as a way to make a political statement or to generate publicity for themselves, Chinese security officials must also contend with the possibility of reprisals to Chinese attacks on CNN's Web site or pro-Tibet sites that have been hit. In previous years, politically motivated attacks by Chinese hackers launched against Web sites in other countries have provoked responses from other hacker groups.

One such hacker war took place in 2001, after a collision between a Chinese fighter jet forced a U.S. Navy reconnaissance plane to make an emergency landing on China's Hainan Island, where the crew was detained. During the hacker war that followed, Chinese and U.S. hackers attacked and defaced hundreds of Web sites in both countries.

So far, there has not been a response from foreign hackers to Chinese attacks against CNN or pro-Tibet Web sites. But hackers may simply be biding their time, choosing to attack or deface Chinese Web sites during the Olympics, a time when any such incident would generate the most publicity.

"I honestly believe something is going to happen, but how bad it could be or what is the scale of it, that's anybody's guess," Fitzsimmons said.