unreasonable.org

It's well-known that the CIA's MK-ULTRA program dosed unwitting people with LSD in the 1950s and 60s as part of their mind control experiments. (Really. I Am Not Making This Up, and it is not loony conspiracy theory history -- read the linked Wikipedia article if you've never heard of MK-ULTRA before.)

However, these experiments were thought to have limited to administration of drugs to one person at a time, or at least only to small groups. But new research into the history of MK-ULTRA provides evidence that a bizarre 1951 outbreak of mass insanity and hallucinations in a southern French village was caused by the CIA spiking the food supply with LSD, rather than by ergot-containing fungus poisoning the bread.

Hundreds of people were affected, dozens were committed to asylums, and at least five died.

According to the Telegraph,

Mr Albarelli said the real "smoking gun" was a White House document sent to members of the Rockefeller Commission formed in 1975 to investigate CIA abuses. It contained the names of a number of French nationals who had been secretly employed by the CIA and made direct reference to the "Pont St. Esprit incident." In its quest to research LSD as an offensive weapon, Mr Albarelli claims, the US army also drugged over 5,700 unwitting American servicemen between 1953 and 1965.

None of his sources would indicate whether the French secret services were aware of the alleged operation. According to US news reports, French intelligence chiefs have demanded the CIA explain itself following the book's revelations. French intelligence officially denies this.