MI5

MI5, officially known as the Security Service, is the UK's domestic intelligence agency responsible for protecting national security. Its main role is to identify and prevent threats such as terrorism, espionage, and sabotage within the UK. MI5 gathers intelligence through surveillance, inquiries, and cooperation with other agencies, assessing risks to ensure the safety of citizens and infrastructure. It operates covertly, balancing national security needs with respecting civil liberties, and reports to the UK government, primarily the Home Office.