Klouchebag is the standard for measuring asshattery online. It was made in response to Klout, the social-game that assigns you a score based on how 'influential' you are online.
Klouchebag uses the ARSE rating system. Anger: profanity and rage. Retweets: 'please RT's, no or constant retweeting, and old-style. Social Apps: every useless checkin on foursquare or its horrible brethren. And English Usage: if you use EXCLAMATION MARKS OMG!!! or no capitals at all, this'll be quite high. My rating: Quite a nice person. And they're right.