Roberts's book explores the world of content moderation, with some in-depth and revealing interviews with the people who actually view hours and hours of horrific content in order to keep it from populating the web. These moderators play a huge role in how we interact with the Internet -- literally determining what we are allowed to see -- yet are largely anonymous and treated as disposable by the corporations who employ them. The people she interviews are reflective: One muses that he was proud of flagging a potential suicide video, which helped save the potential victim, but did the social media site create the circumstances for such videos to happen in the first place? An engaging exploration of a difficult topic, and one that social media companies themselves would assuredly rather not have us think about.