Facebook, Twitter and other online services set rules for users' posts not just to flag individual statements, but more broadly, to ensure they're complying with the law, to help define their businesses and to protect their users.
Driving the news: Public debate over online speech peaked again with Kanye West's ban from Twitter and Elon Musk's willingness to bring Donald Trump back to that service if he becomes its owner. But public understanding of why social networks moderate content remains murky.
