Every user signing up for Facebook agrees to a set of terms and conditions about what can and can’t be posted. For example, you can’t sell weapons, post nude photos, or abuse people on Facebook. Hate speech and threats of violence are explicitly prohibited. Despite its recent claims to be free-speech fundamentalists, Facebook takes down such content all the time. But when it comes to powerful people the company doesn’t want to upset, it cites free speech as a way to justify violating its own rules.