The pursuit of folk devils frequently intensifies into a mass movement that is called a moral panic. When a moral panic is in full swing, the folk devils are the subject of loosely organized but pervasive campaigns of hostility through gossip and the spreading of urban legends. The mass media sometimes get in on the act or attempt to create new folk devils to create controversies (see To Catch a Predator). Sometimes the campaign against the folk devil influences a nation's politics and legislation.
The concept of the folk devil was introduced by sociologist Stanley Cohen in 1972, in his study Folk Devils and Moral Panics, which analysed media controversies concerning Mods and Rockers in the United Kingdom of the 1960s. The basic pattern of agitations against folk devils can be seen in the history of witchhunts and similar manias of persecution; in many predominately Protestant countries, there is history of anti-Catholicism in which many Catholics were seen as folk devils; minorities and immigrants have often been seen as folk devils; in the long history of anti-Semitism, which frequently targeted Jews with allegations of dark, murderous practices, such as blood libel; or the Roman persecution of Christians that blamed the military reverses suffered by the Roman Empire on the Christians' abandonment of paganism.