Chilling Effect
The deterrence of constitutionally protected speech by the threat of legal consequences, even when the speech would not actually be prohibited.
A chilling effect occurs when the threat of legal sanction causes speakers to self-censor — to refrain from constitutionally protected expression out of fear that their speech will attract prosecution, civil liability, or other adverse consequences.
Chilling effects are constitutionally significant because they suppress protected speech without any direct government action targeting the specific expression. A law that is vague about what it prohibits, or that imposes severe penalties for borderline speech, may cause speakers to avoid a wide range of protected expression rather than risk being caught on the wrong side of the line.
The Supreme Court has used the chilling effect rationale to justify several distinctive First Amendment doctrines: - Overbreadth: Laws that reach substantially more speech than they could constitutionally prohibit are struck down even when the specific application would be constitutional, to avoid the chilling effect on protected speech - Vagueness: Laws that are vague about what they prohibit are struck down under the First Amendment because vagueness creates especially severe chilling effects - Prior restraint doctrine: The preference for subsequent punishment over prior restraint partly reflects the greater chilling effect of pre-publication censorship
Chilling effects are also cited in arguments against aggressive platform content moderation — the argument being that the threat of deplatforming chills speakers' willingness to engage with controversial topics.