A person who comments on a post and doesn't feel like their post got enough praise, thus comments again for people to notice them.
Joe Blow is feeling sad
Douche: cuz your gf dumped you? haha.
Jill: Feel better!
Larry: Cheer up dude!
Douche: get a life loser!
Hilary: Wow Douche, screw off you comment attention whore. Where do you find these assholes Joe?