Secret service This article is about the form of government policing . For the television series , see The Secret Service . Because of both the secrecy of secret services and the controversial nature of the issues involved , there is some difficulty in separating the definitions of secret service , secret police , intelligence agency etc . For instance a country may establish a secret service which has some policing powers ( such as surveillance ) but not others . A secret police may also be said to be a secret service . The powers and duties of a government organisation may be partly secret and partly not . The organisation may be said to operate openly at home and secretly abroad , or vice versa . The most prominent organization bearing this title is the United States Secret Service , but it is a law enforcement and protective agency , and not a secret police or intelligence agency . The CIA fulfills that role , to some degree . The British Secret Intelligence Service ( MI6 ) , is sometimes referred to as a 'secret service' , and this term was used for the title of the James Bond book and film On Her Majesty 's Secret Service . See also Espionage History of secret police forces List of intelligence agencies international and by country Mass surveillance  This government -related article is a stub . You can help Wikipedia by expanding it . Categories : Government stubs | National security In other languages : Česky | Français | 日本語 | Slovenčina 