Who: Novelist, screenwriter behind The Canyons
Tweeter: True, he's not a film personality, but the author of Less Than Zero and American Psycho is a prolific tweeter of film criticism and crazy. He loves Silver Linings Playbook, thinks Kathryn Bigelow only gets attention because she's a woman, and is, generally speaking, a notorious wild card without a filter. Gotta have one of those in your feed.