This type of individual firmly believes that their mundane thoughts are actually interesting or relevant to those they twitter to. This person wastes time telling others how they are wasting time.
Bill: "Dude, I just got a twitter from Hank telling me he's scoping out some hot women at a club in Reno."
Ted: "He's such a twitter-twat! He'd rather take the time to tell you about those hot women than actually try to hook up with them? Wait... You have a twitter account? You're a twitter-twat, too! Fuck, I need some new friends...!"
An individual that goes WAY beyond simply being a fan. This individual would rather dress up in their team colors, ignore the hot babe they are with and yell at the tv about the stupidity of the refs/coaches/players every call. They feel each play should have resulted in a touchdown and honestly can't believe it didn't. These individuals are often found sitting next to you at the bar and force you to root against their team, even if it is your team also.
Sports Douche: "Why the hell did the running back run up the middle??? Couldn't he see the hole clog up before he got to it? They should have called a pass on the play! It would have been an easy 6!!"
Girlfriend (thinking to herself): Why am I with this Sports Douche? He can't even see I'm not wearing a bra! Doesn't surprise me, he couldn't even see that both receivers were double covered with the safety over the top. Clearly they had to run the ball and the defense was just that good on that play. Idiot... Hmm, who's that guy over there...???
Worn by sports douches when they refuse to believe their team/player did something wrong even when video replay CLEARLY showed the flag/call was correct and 5 million viewers with IQ's above a hamster's can easily agree with it.
Referee: "After further video review, the players foot was out of bounds; pass is ruled incomplete."
Sports Douche: "What?! How can that be. He was clearly in bounds. The ref couldn't see the difference between the guys white shoes and the white sideline... That's a bull s#^t call! And why the hell did the coach even call that play...?"
Objective Observer: "Dude, sit the hell down, shut up and take off those Replay Rose Goggles. He was clearly out of bounds. The video replay CLEARLY showed it, you dumbass! It's guys like you that make me want to root against our team..."