The government tested the effects of LSD on unwitting U.S. and Canadian citizens.

Under the code name "MKUltra," the U.S. government ran a human-research operation within the CIA's Scientific Research Division. Researchers tested the effects of hypnosis, sensory deprivation, isolation, torture, and most memorably, LSD, on U.S. and Canadian citizens. Most had no idea.
To conduct these experiments, the CIA paid prisons, hospitals, and other institutions to keep quiet. The department even enticed heroin addicts to participate by offering them heroin, according to documents from a joint hearing to subcommittees of Congress, where President Kennedy spoke.
That day, he regaled Congress with "chilling testimony." Over 30 universities became involved in various studies. Notably, many lacked oversight by medical or scientific professionals. At least one participant, Frank Olsen, died, reportedly from suicide after unknowingly ingesting LSD.
In January 1973, then CIA Director Richard Helms ordered the destruction of all documents pertaining to MKUltra. When Congress looked into the matter, no one, not even Helms, could "remember" details. Through a Freedom of Information Act (FOIA) request, more documents were located, but the full timeline remains incomplete.
The events inspired investigative journalist Jon Ronson's best-selling book, "The Men Who Stare At Goats," now a movie of the same title starring George Clooney