…Created immediately after the 1964 coup d’état which led to 21 years of dictatorship in Brazil, the SNI quickly became the centre of a complex repressive apparatus put in place by the military. Established by Law No. 4,341 on June 13, 1964, the legally defined purpose of the agency was to “advise the President of the Republic” regarding information and counter-information activities.” In practice, SNI agents carried out all kinds of activities linked to political repression, participating in street operations and torture.

The institution was created by General Golbery do Couto e Silva, one of the main figures in the coup.

The historian Priscila Brandão, author of the book “SNI and Abin: A Reading of Brazilian Secret Services Throughout the Twentieth Century,” explains that the body expanded rapidly after its creation. “The SNI, like an octopus, spread throughout the State. Where it thought it needed to, it created a new agency, ” she explained.

Soon, the agency had a presence in civilian ministries, universities, and public companies and coordinated with the intelligence services of the three armed forces, the National Security Council, and the state-level security secretariats…

Source: In Brazil, the intelligence services spied on over 300,000 citizens during the military dictatorship · Global Voices