Twitter sometimes feels like a Superfund site for toxic psychic energy, where misogynists, racists, homophobes, and assorted bigots gleefully broadcast their hate and disturbingly graphic death threats are handed out over minor perceived sleights that in pre-Twitter days may have demanded, at the most extreme, a flipped bird. Over a weekend where the acts of a woman-hating mass murderer and a hashtag meant to convert the situation into a teachable moment provoked outrageously misogynistic responses on social media that confirmed just how near the mainstream some of his views were, that feeling was particularly acute.