A Modern Witch Hunt
Most sensible people would support the idea of outing those who kidnap and torture children. But in the 80s and 90s, that seemingly sensible idea began to spiral out of control. Apparently, many people were convinced that there was an underground ring of child abusers who also happened to worship Satan on their off time.
The paranoia regarding this supposed cult grew out of control and developed into a sort of modern-day witch hunt. Unfortunately, the theory was not grounded in anything but speculative fear, and many innocent people had their lives ruined because of it.