Sidney Gottlieb and Allen Dulles oversaw MKUltra experiments from the 1950s to 1973 that administered LSD and other drugs to unwitting US and Canadian citizens to test reactions and try to develop truth serums and sleeper agents. Methods included administering LSD without consent and asking subjects questions to see if they would answer truthfully or follow orders while under the influence, as well as other experiments involving electroshock, drugs, hypnosis and harassment. Though most documents were destroyed, it is known that some subjects died and thousands were exposed to dangerous substances without consent during the program.