Facebook absolutely does all the things you listed, and more; much more. While I agree that their incentives are often at odds with content enforcement, it is

Facebook absolutely does all the things you listed, and more; much more. While I agree that their incentives are often at odds with content enforcement, it is not a "just so" problem to be fixed with a better methodology or algorithm, and if you can think of it in an HN post I assure you they have already tried it in some fashion. P.S. Former Facebook employee