A revealing and gripping investigation into how social media platforms police what we post online—and the large societal impact of these decisions 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.   In this revealing and nuanced exploration, award–winning sociologist and cultural observer Tarleton Gillespie provides an overview of current social media practices and explains the underlying rationales for how, when, and why these policies are enforced. In doing so, Gillespie highlights that content moderation receives too little public scrutiny even as it is shapes social norms and creates consequences for public discourse, cultural production, and the fabric of society. Based on interviews with content moderators, creators, and consumers, this accessible, timely book is a must–read for anyone who’s ever clicked “like” or “retweet.”