I'm with the dude, on that one.

Technically, isn't accessing any online account that is not your own a crime, regardless of whether it's a game or a bank account?

Aside from that, even though it seems sort of petty because it's "just a game", it's an attack on the personal property of another. There are any number of hobbies and pastimes that are important to people, and the hours and attention they put into them have value, even if it can't be assigned monetary worth.

In a more material, uncyberspacey sense, things like photo albums, address books, personal artwork and the like have no cash value. But if some vindictive bitch (or bastard) tosses them into the furnace for revenge, they've destroyed something irreplacable, or only replaceable through great time and effort.

I suppose it would depend on the individual what sort of things are worth bringing legal action against, but I would hope the ability to do so is there for those who suffer such petty attacks.

...and this is coming from a guy who is violently disgusted with the ridiculous, frivolously litigious society we have become. (personally, I'd find a much more creative way to get my pound of flesh)