Moral panic
Etymology
The concept was developed by sociologist Stanley Cohen in his 1972 study Folk Devils and Moral Panics, about the media-driven reaction to the Mods and Rockers in 1960s Britain. Cohen described how a "folk devil" is identified and demonized in a self-amplifying spiral of concern. The phrase joins "moral," invoking threatened values, with "panic," the disproportionate fear.
noun phrase · /MOR-ul PAN-ik/
A wave of public alarm in which a group or trend is cast as a grave threat to society, out of proportion to the actual danger.
What it names
It gives a name to the recurring cycle where media, authorities, and the public amplify each other into fearing a "menace" — from comic books to video games to dance crazes — that later looks overblown.
Example
The claim that a new app was "destroying a generation" had all the markings of a moral panic, heavy on anecdote and light on evidence.
Related idea
A moral panic is the disproportionate public reaction; the folk devil is its cast villain — the specific group, subculture, or object onto which the collective anxiety is projected.