The rule of law in cyberspace currently faces serious challenges. From the democratic system to the exercise of fundamental rights, the Internet has raised a host of new issues for classic legal institutions. This book provides a valuable contribution to the fields of international, constitutional and administrative law scholarship as the three interact in cyberspace.

The respective chapters cover topics such as the notion of digital states and digital sovereignty, jurisdiction over the Internet, e-government, and artificial intelligence. The authors are eminent scholars and international experts with a profound knowledge of these topics. Particular attention is paid to the areas of digital democracy, digital media and regulation of the digital world.

The approach employed is based on a comparative perspective from Germany, the Netherlands, Italy, Portugal and Brazil. One particular focus is on how various legal systems are coping with increasing difficulties in the exercise ofdemocracy with regard to disinformation and hate speech. The roles of legislators, the judicial system and public administrations are analysed in the light of the latest cases, conflicts and technologies.

In addition to this comparative approach, the book explores the evolution of rule of law in cyberspace and the upcoming new legal regimes in the European Union and Brazil. Special care is taken to offer a critical review of both the literature and the latest legal solutions adopted and being considered regarding the regulation of cyberspace from a constitutional and administrative perspective.

Given its scope, the book will be of interest to researchers and scholars in the field of digital law whose work involves constitutional problems in cyberspace and/or practical problems concerning the regulation of social networks and online commerce.

Carlos Blanco de Morais holds a PhD from the Faculty of Law of the University of Lisbon where he is Full Professor of Constitutional Law and International Public Law. He occupies various positions at the Faculty, such as Head of the Department of Public Law and Scientific Coordinator of Lisbon Public Law Research Centre(CIDP).- He is Senior Juridical Consultant of the Portuguese Council of Ministers Juridical Centre.

Gilmar Ferreira Mendes is a Justice of the Federal Supreme Court (STF) and Professor of Constitutional Law at IDP in Brazil. He holds a Ph.D. Degree from the University of Münster (Germany).

Thomas Vesting, Chair of Public Law, Law and Theory of the Media, Johann Wolfgang Goethe University, Frankfurt am Main. Associate Member Cluster of Excellence "The Formation of Normative Orders". 2017 Awarded honorary doctorate (IDP - Brazil).

- Introduction. - Part I Democratic Constitutionalism in Cyberspace.- Digital Democracy: A Threat to the Democratic System or Oxygenation of Representative Democracy and Free Speech?. - Digital Constitutionalism and Constitutional Jurisdiction: A Research Agenda for the Brazilian Case. - The Crisis of the Representative Democracy in the Face of Digital Democracy. - Rule of Law, Democracy and New Technologies. - Freedom, Democracy, Digital Government and Human Development. - The Digitization of Government and Digital Exclusion: Setting the Scene. - The Impact of Artificial Intelligence on the Structures of the Modern Public Sphere. - Part II The Threat of Disinformation and the Role of Social Networks. - Fake News and the 2018 Brazilian Presidential Election. - Political Speech, Freedom of Expression and Fake News. - Disinformation and Journalism. - Social Networks andthe Exercise of Fundamental Rights: Public Administration and the Digitalization of Fundamental Rights. - Freedom of Expression in the Age of Digital Platforms: Change of Paradigm?. - Online Hate Speech and the Role of Digital Platforms: What Are the Prospects for Freedom of Expression?. - Hate Speech and Social Media. - Dont Shoot the Message: Regulating Disinformation Beyond Content. - Models of Legal Liability for Social Networks: Between Germany and Portugal. - Self-Regulation and Public Regulation of Social Networks in Portugal. - Cyber Courts for Social Media As a New Institutional Dimension of Media Freedom?.