In the context of the CBRN threat, drones, considered by international and national legislations as real aircrafts, due to their versatility, availability, ease of modification and use, have attracted the attention of the author who has, in the present book, outlined and deepened both the possible applications in attacks by terrorist groups and the possible uses by the Police or other State apparatuses engaged in anti- terrorism action. Some European projects on the use of drones are reported.