E-Commerce News: Security: UFO-Seeking British Hacker May Face US TrialSadly, too many people still misunderstand computer intrusions. They think that "no harm, no foul", if nothing is stolen or broken, that they have no legal liability. But they are wrong. The intrusion itself, even without proveable damages is enough. Think of it this way. If someone broke into your house and walked around, but didn't steal anything or break anything, should they be allowed to walk away without consequences? No.
The intrusion into your space, your home, your secure place, is enough to support the commission of a crime.
It's the same here.
While some people may think that the reason for the "hacking" was noble, or funny, the act itself is all that matters.