In former Czechoslovakia, State Security (, ) or StB / ŠtB, was a plainclothes secret police force from 1945 to its dissolution in 1990. Serving as an intelligence and counter-intelligence agency, it dealt with any activity that could possibly be considered anti-communist.
From its establishment on June 30, 1945, onward, the StB was bound to and controlled by the Communist Party of Czechoslovakia. The communists used the StB as an instrument of power and repression: the StB spied on and intimidated political opponents of the Party and forged false criminal evidence against them, facilitating the Communists rise to power in 1948. Even then, before Czechoslovakia became a communist state, the StB used forcing confessions by means of torture, including the use of drugs, blackmail and kidnapping. After the coup d'état of 1948, these practices developed under the tutelage of Soviet advisors. Other common practices included telephone tapping, permanent watching of apartments, reading mail, house searches, surveillance, arrests and indictment for so-called "subversion of the republic".