9. IRA Loyalists IRA was one of the nastiest terrorist organizations in the world. Over the course of several years, they carried out assassinations and bombings that left dozens dead and hundreds wounded.
In 1971, British forces swooped on Northern Ireland and rounded up 342 suspected Loyalists.
All of them were interred in a prison camp without trial and with no release date, at which point the torture started.
After being beaten half to death, inmates had a hood shoved over their heads before being made to stand spread-eagle against a wall.
There they were bombarded with loud, disorientating white noise scientifically designed to induce psychosis.
Sleep was forbidden.
Food and water were nowhere to be seen.
According to the BBC, 1,900 people would eventually pass through the camp in a dark chapter now almost scrubbed out of history.