This introductory chapter sets the theoretical backdrop for the theme of the book and subsequent chapters. The chapter commences from the long pedigree of Western political theory and its focus on the security and safety of citizens. Providing external and internal security for the citizens has been considered the most central task of states and governments at least since Thomas Hobbes (1588–1679) onwards. Even the most libertarian branches of political thought agree that catering for this security need justifies the very existence of states. This fundamental framework as such has not changed much over the centuries, one could argue, but the very concept of security has undergone transformations. Research literature refers to the widening of security discourse, where the fulcrum of security shifts from state security to human security and includes issues traditionally considered to be outside of “hard security”. At the same time another trend, the transformation of government into governance, has changed the logic of how this security is provided. The introductory chapter scrutinizes these two transformations and how they manifest themselves in the book’s chapters. The interplay between multi-level governance and the widening of security discourse is addressed in the two parts of the book: first part is the theoretical one, scrutinizing various aspects of widening security discourse and challenges posed by emerging technologies. The second part delves deeper into the practical cases from different cities showing how some of these challenges have been met.