In 2017 Facebook said it would hire 3,000 people to review videos and other posts, on top of the 4,500 people Facebook already tasks with identifying criminal and other questionable material for removal. But that's just a drop in the bucket of what is needed to police the social media platform, said Siva Vaidhyanathan, author of "Antisocial Media: How Facebook Disconnects Us and Undermines Democracy." If Facebook wanted to monitor every livestream to prevent disturbing content from making it out in the first place, "they would have to hire millions of people," something it's not willing to do,...