Moral panics on social media are fueled by signals of virality.

Moral panics have regularly erupted in society, but they appear almost daily on social media. We propose that social media helps fuel moral panics by combining perceived societal threats with a powerful signal of social amplification-virality. Eight studies with multiple methods test a social amplification model of moral panics in which virality amplifies perceptions of threats posed by deviant behavior and ideas, prompting moral outrage expression. Three naturalistic studies of Twitter (