Anonymoids- I think that's a good name for those who act like a*holes from behind their veil of anonymity.
I don't run into that much here- I realize most of my anonymous commenters are simply either protecting their privacy, avoiding setting up a Blogger profile (which amounts to the same thing), or are hilarious spammers. None of which are generally hostile (even when they disagree with me).
But on other, popular, blogs I see lots of anonymoids. I even have my own anonymoid fanboy on one blog where I occasionally comment. He rarely lets a comment go by without suggesting that he is shocked I haven't yet gone on a killing spree before offing myself. I've taken to just giving him a virtual pat on the head like a yapping puppy any time he responds to me, which seems to have taken away some of his enthusiasm. Poor little guy!
I think if you attract the attention of anonymoids, especially of the rabid statist variety, it just shows you are probably doing something right. Think of them as an award on your wall. Their hostility and stupidity just makes you look better.