This book is about rights and powers in the digital age. It is an attempt to reframe the role of constitutional democracies in the algorithmic society. By focusing on the European constitutional framework as a lodestar, this book examines the rise and consolidation of digital constitutionalism as a reaction to digital capitalism. The primary goal is to examine how European digital constitutionalism can protect fundamental rights and democratic values against the charm of digital liberalism and the challenges raised by platform powers. Firstly, this book investigates the reasons leading to the development of digital constitutionalism in Europe. Secondly, it provides a normative framework analysing to what extent European constitutionalism provides an architecture to protect rights and limit the exercise of unaccountable powers in the algorithmic society. This title is also available as open access on Cambridge Core.