Dubbed "March Madness," the 64-team tournament, which officially gets under way March 15, is one of the world's most widely watched sporting events and will fuel almost US$4 billion in wagers before it wraps up April 2.

An explosion in the number of sports and gambling Web sites, along with a major increase in high-bandwidth features, such as real-time scores and streaming video, pose a threat to businesses, said Websense. The number of sports-related Web sites is up 31 percent over last year, while online gambling sites have grown by 56 percent since March 2006. Put the two together, and "midsize companies can expect to see a considerable drain on employee productivity and network bandwidth during the NCAA tournament," Websense said.

Online gambling, even with recent crackdowns on the practice in the U.S., is huge. According to estimates, approximately $1.3 billion will be gambled during the tournament at online sports books. An estimated $2.4 billion will be wagered illegally, and another $90 million will be bet in Las Vegas.

Corporations and users should also expect hackers to take advantage of buzzer-beater fever, said Websense. Last month, for example, the Web site of the the Super Bowl was hacked and used to deliver malicious code to unsuspecting visitors. In July 2006, criminals set up a fictitious site that looked like the official FIFA World Cup URL; that site was used to spread malware, too.

Historically, identity theft campaigns have also tied themselves to sporting, including bogus come-ons for World Cup tickets and e-mails trying to trick buyers of NASCAR merchandise on online auction house eBay.