Some people (mostly Liberals) just can't help themselves, its a form of narcissism, where the individual thinks himself and his thoughts so important, that it trumps the normal conventions of civility.
For cryin out loud, look at Sheehan, look at the liberal kooks who insist on distrupting things, its all about Me, My Thoughts, My Feelings!
It is a mental disease.
Don't leave out the loonies like Fred Phelps, who go around disrupting funerals all the time...