The book "Police Action and Citizen Protection: Theoretical and Jurisprudential Approach" deals with the subject of the exercise and limits of police action in maintaining public order and security, through the classification of police actions and the investigation of their application in modern technologies (drones, cameras, GPS) and evaluates the laws on gatherings and video surveillance. At the same time, the work proposes a Police Procedure Code and the creation of judicial police in Greece. The work is absolutely necessary for students of all Security Schools, lawyers, judges, and especially the Citizen himself.