I just think it's 1)normal when you've been nice til then and can't stand it anymore, 2)not often at all with Matt. Most of the time he sends super nice tweets or short ones to make the person happy. I've seen more random comments by most celebs I follow honeslty. But anyway...
Kim I agree they choose the job, doesn't mean they have to accept everything it comes with, especially not being insulted or "attacked" because of something stupid like "working and not having time to answer every tweet or following anyone on twitter".
Johnny Depp. He's THE man. But he avoids those stuff so yeah, it might help to stay sane.