Idea: Large-scale cracking contests as a sport.
You have an attack team and a defense team. There's some kind of system (Web site, application, database, email, whatever) that is the focus of the whole thing.
The defense team gets a few hours to harden the system, then the attack team gets some time to try to break in and achieve one of several objectives. The attackers get more points the more they accomplish (theft > destruction > DoS). The defenders get more points the longer they hold out.
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