"Most users want their Twitter feed, Facebook page, and YouTube comments to be free of harassment and porn. Whether faced with 'fake news' or livestreamed violence, 'content moderators'--who censor or promote user-posted content--have never been more important. This is especially true when the tools that social media platforms use to curb trolling, ban hate speech, and censor pornography can also silence the speech you need to hear. [The author] provides...