Someone who, while posting on twitter, insists on using an "@ mention" to address a celebrity, company, website, or otherwise rather than just state their name. This becomes especially irritating when the username of a person or thing is different than their real name.
*Did anyone see the @Google homepage today? so cool
*Just got back from the @UsherRaymondIV concert. amazing.....that guy can really sing!
Good god she's an @ddict