In the 1950s and 1960s there was something called “Project MKUltra” that the CIA ran a secret illegal human experimentation program to test mind-control techniques , dosing unsuspecting people with LDS and other drugs.
This was thought to be a conspiracy for years, but was later found to be true. In 1975 there were public hearings that proved to be true.
I often wonder how much truth is to the so called conspiracy theories today will be found out to have truth to them in the future.
From Pity to Praise 