A place for stories where anypony, especially the princesses, end up with a group of overzealous fanatics being crazy, perhaps even evil, in their name. Is there some group of ponies who believe that the world must be "cleansed of abominations in the name of Celestia"? They don't need to believe that they're doing "good", either! Maybe there's a cult following Luna, trying to turn her back into Nightmare Moon, for example. This can also happen for Twilight, Discord, Cadence, the other Elements, Sombra, Chrysalis, anyone really.

Bonus points if the so-called "leader" tries to stop them and they claim that he/she has been blinded, and they must open his/her eyes!