Well I guess that's one thing you and those on death row have in common.
In those few words you have summed up the issue: At what point is violence an acceptable course of action?
Violence is only justifiable in self defense, both legally and morally. In nearly every case I can think of, the first person to resort to violence is the 'bad guy'. And to resort to violence simply because someone disrespected you is one thing, but you would intentionally commit the ultimate act of violence simply because someone insulted you? Maybe you're just in a bad mood and its easy to say these things on the net, but if you really mean it, you're far more of a menace to the civilized society you claim to like than the person you would have killed.
Not because of the insult, but because they were behaving in a manner that indicated extreme irrationality. Unfortunately, to wait until I'm actually attacked would essentially be to bet my life on the other person's sanity--which, as I've pointed out, is demonstrably gone.
"He who shoots first writes up the incident report. He who shoots second is likely to never get a chance to shoot at all."
There are certain things that I don't do because they are likely to convince people that I am out to kill them. Screaming obscenities in their face is one of those things.