In the 1950s, UK intelligence body MI6 ran an experiment where volunteers, under the impression that they were participating in a research effort to find a cure for colds, were given a liquid to drink. Turns out that the liquid was laced with LSD and some of the participants freaked out. Five decades later, MI6 has paid three men for their troubles. According to the BBC News, the settlement for each is thought to be less than £10,000. From the BBC News:
A spokesman for the Foreign Office, which oversees MI6, said: "The settlement offers were made to the government on behalf of the three claimants which, on legal advice, and in the particular circumstances of these cases, the government thinks it appropriate to accept…"
The research was carried out after British and American governments thought the Soviet Union had developed a "truth drug" which could compel spies and servicemen to yield up important secrets.
MI6 scientists decided to test LSD, the closest thing they thought they had to a truth drug, on volunteers to see how they reacted.
