Cults are pretty scary. Most people don’t exactly set out to join one, but it happens to good people anyway. And bad ones too. Whatever kind of person you need, you can find a story from these examples, I’m sure.
Some terrifying cults are so well-known they can be described with a single word: Manson, Waco, Jeffs, Jonestown. Others may not be as iconic—at least in America—but still provide plenty of nightmare material.
Source: The 5 Scariest Cults in Modern History