Is Twitter now such a rough-and-tumble place that even a man as manly as Armie Hammer can\u2019t survive there? On Monday, after calling a BuzzFeed piece about him \u201cbitter AF,\u201d Hammer peaced out of the social network. He\u2019s hardly the first person to have fled the platform\u2014the Twitter hiatus has been a certifiable Thing this year, the online equivalent of a juice cleanse\u2014but his reasons for fleeing seem a little less admirable than the usual ones.