Social media had a considerable, possibly decisive, role in Fox News firing Bill O’Reilly, host of maybe the most popular and most reviled show in cable news history. If O’Reilly did not pioneer the television news genre of ‘angry man believes the truth means just repeating a prejudice or an opinion as loudly as possible’, he was perhaps its most proficient exponent. He was simply louder and more belligerent than anyone else. And also, it turns out, a serial harasser of women. For decades. Social media is celebrating his scalp because a sustained online campaign scared off enough advertisers to persuade Fox to cut their losses.