This book aims to answer a simple empirical question in a complex environment. Is Internet regulation a paradigm of constitutionally responsive co-regulation? Within the question, I unpack first what forms of regulation are present in the governance of the Internet, based on case studies. I define and examine what responsive regulation, and specifically co-regulation, entails, and how it contributes to protecting constitutional rights within regulatory organizations. Finally, I assess the extent to which Internet co-regulation is a paradigm of such forms of regulation, as compared to, for instance, financial or environmental regulation.