Another one you should add to the list is people who feel the need to comment on your shit and explain how you are wrong because somehow you burned a hole in their special pet interest, or they want to tell the whole world they are smarter than you.  Or, not the whole world, but the people who read the comments--and that list is shorter than the list that reads the article.  The comment section is for assholes.
Oh, and another one to add is people who don't understand irony.