Evil minorities/heretics sabotaging society, for example by poisoning the well
Do We Have This * Early Development Phase
Basically, this trope is about the sneaky kind of terrorism which try to pass itself off as accidents, general misfortune, aimless delinquency, or unintentional phenomena such as pollution and disease. While throwing a dead animal in the well or otherwise poisoning the local water supply is a classic method, there are also many other ways. The villain does it for revenge, For the Evulz, or because of a deep conviction that that the victims are bad and ought to be harmed. Such a villain is not the bomb-throwing, slogan-shouting kind of person who announce themselves as being a threat. Instead, Paranoia Ensues as they try to stay unnoticed - while usually pretending to be harmless and friendly, even allies. In medieval times, this trope was often used on fictional Jewish characters, and used to spread fear and hatred against the Real Life Jews. In modern media, this villain is normally unaffiliated or belong to a group that doesn't resemble any real life group. Using this trope to smear Real Life individuals and groups is known as Poisoned Well Fallacy.