what are situations where a particular group is thought to be a danger or menace to society

Answer: Moral panics.
Explanation:
A moral panic is a sense of fear among many people that something or someone evil endangers the security of society.
A moral panic occurs when an event, person or group of people are portrayed as a menace to societal beliefs and values. It´s the case the belief in the widespread ritual abuse of women and children by satanic cults.