Facebook “farms” its users for data: the more they produce – the more “user engagement” there is, in other words – the better. Consequently, there is an overriding commercial imperative to increase levels of engagement. And it turns out that some types of pernicious content are good for keeping user-engagement high: fake news and hate speech are pretty good triggers, for example. So the central problem with Facebook is its business model: the societal downsides we are experiencing are, as programmers say, a feature, not a bug.