During the 1970s, when Northern Ireland was gripped by near-civil-war, British military intelligence staged the evidence of "black masses" in order to create a Satanism panic among the "superstitious" Irish to discredit the paramilitaries.
The secret history of imaginary Irish Satanism is documented in
Black Magic and Bogeymen: Fear, Rumour and Popular Belief in the North of Ireland 1972-74, a new book from Sheffield University's Richard Jenkins, who interviewed Captain Colin Wallace, the former head of British Army "black operations" for Northern Ireland.
Apparently, the thinking was that both the Roman Catholic and Protestant churches would not tolerate Satanism, and that the idea of Satanism had entered the public consciousness thanks to movies like The Exorcist and The Devil Rides Out. If the tabloid press could convince the nation that paramilitaries were engaged in Satanic rituals, their public support would ebb.
"I think that Wallace and the Information Policy unit had two main objectives. First, it was to encourage a devout population to think that the Troubles had opened a door to 'dark forces' and to have them blame the paramilitaries by implication. The logic being: the ungodly paramilitaries caused the violence, the violence has encouraged all kinds of horrible things, ergo the devil, Satan and all that, although I don't think that was ever going to fly.
"Second, there was the bonus of keeping people, especially teenagers and kids, off the streets at night."
The years 1972-74 were among the bloodiest of the Troubles and a period when Northern Ireland teetered on the brink of civil war. It was also the era when Ulster loyalist paramilitary groups started carrying out ritualistic-style torture killings of Catholics and political opponents.
Satanic panic: how British agents stoked supernatural fears in Troubles [Henry McDonald/The Guardian]