In Chilling Effects, Jonathon W. Penney explores the increasing weaponization of surveillance, censorship, and new technology to repress and control us. With corporations, governments, and extremist actors using big data, cyber-mobs, AI, and other threats to limit our rights and freedoms, concerns about chilling effects – or how these activities deter us from exercising our rights – have become urgent. Penney draws on law, privacy, and social science to present a new conformity theory that highlights the dangers of chilling effects and their potential to erode democracy and enable a more illiberal future. He critiques conventional theories and provides a framework for predicting, explaining, and evaluating chilling effects in a range of contexts. Urgent and timely, Chilling Effects sheds light on the repressive and conforming effects of technology, state, and corporate power, and offers a roadmap of how to respond to their weaponization today and in the future.