And about the alcohol thing - I've always said that alcohol doesn't really change you - it just amplifies your personality. It may have just given them the balls to do what they felt entitled to - and that's what I have a problem with.
That sounds good on paper, but not true for many in reality. Don't get me wrong, just because you're overly intoxicated does not make you 'not liable' for your actions. You were the one that decided to, 'overindulge'. But I know folks that have done things while intoxicated that do not fit there character in any way. I agree with you if your talking "buzzed", as I feel you are still in control at that point (just have less inhabitions). On the other hand, when people are "butt freak'in wasted", they are unpredictable.
I will say this: If they made the heart and totally marked threw (essentially erased) other peoples signatures, yes, that is very rude. Still not worthy of public humilation, though (IMO). Maybe I'm just a softie.