We are, as always, indebted to our families and especially grateful for their support during the book’s final, frazzled push. Thank you. Thank you, as well, to the friends, guides, and sounding boards who help keep us rooted: M&V, Everett, Stevie, Maple, D&C, Kato, Wesley, Anne, Mark, Theresa, Ashley, Joanne, Kelly, Sophie, Sarah F, Jo, LB, Ang, Cheryl, Wendy, Janet, D&C, El, Cal, S&R, John, Jeff, Cate B, A, AG, D&A, M&E, Becky, E&M, R&L, Sarah, S, G, and P. We are deeply grateful to the thinkers who have contributed to this project in various ways, particularly danah boyd, Jessica Beyer, Alice Marwick, Becca Lewis, Claire Wardle, Danielle Citron, Shireen Mitchell, Joan Donovan, Jason Koebler, Abby Ohlheiser, April Glaser, Brandy Zadrozny, Ezra Klein, Gabriella Coleman, Nikki Usher, Daniel Kreiss, and the book’s reviewers. Dan Engber, Phillips’s editor at Wired, is similarly excellent. Patrick Davison, Mike Rugnetta, and Stephen Bruckert, who offered such unflinching reflections in chapter 2, deserve special recognition and many thanks. The project has unfolded organically through countless conversations with journalists and scholars in the United States and abroad. Thank you to all, with special thanks to everyone at the Fluminense Federal University for being such gracious hosts—Viktor Chagas and Natalia Dias in particular. We are also extremely grateful for our dynamic, generous colleagues in the College of Charleston’s Communication Department and Syracuse University’s Communication and Rhetorical Studies Department; neither of us could say enough good things about our respective chairs, Jen Kopfman and Chuck Morris. And to our students, sheltered in place: thank you for your humor, grace, and patience. Our warmest thanks, as well, to Data & Society’s Media Manipulation Initiative and its funders Craig Newmark Philanthropies, the Ford Foundation, and the News Integrity Initiative at the Craig Newmark Graduate School of Journalism at the City University of New York; Data & Society’s MMI published Phillips’s “The Oxygen of Amplification” report in 2018, and we’ve woven portions of that work into chapter 3. Big thanks, also, to the Knowledge Futures Group and the PubPub team, especially Catherine Ahearn and Quincy Childs, for giving the book an early home. And to everyone at the MIT Press; we are profoundly grateful for your care and concern and willingness to let the book meet the moment. María Garcia, Judy Feldmann, and William Henry, thank you. Gita Manaktala, you’re our hero. Finally, Ryan, thank you. Whit, thank you.