The book examines the evolution of Italian legislation on private security, tracing the transition from the traditional rural guard to the modern figure of the guard as a professional. It explores the main national and European legal sources, with particular focus on Presidential Decree 153/2008 and Ministerial Decree 269/2010, which establish the standards for private security firms. The text delves into the concepts of subsidiary and complementary security, highlighting the "Mille occhi sulla città" protocol as an example of public-private collaboration. Finally, it analyzes the social impact of the new laws, including their implications for employment and the perception of insecurity.