What is the main purpose for holding such a special contest?

A computer hacker’s contest dubbed "Defacers’ Challenge" appears to have caused no serious damage today. About 300 attacks were reported minutes after the worldwide contest began but no big companies reported being hit. Security officials said a number of small, unsecured websites were knocked offline. The founder of an Estonia-based site that monitors attacks by hackers says his site was down for much of the day because a large number of legitimate visitors as well as suspected hackers overloaded his servers. Hackers were encouraged to prove their expertise by taking down as many websites as possible during a six-hour period.