Prior Restraint
Government action that prevents speech or publication before it occurs, rather than punishing it afterward.
A prior restraint is a government action — typically a court injunction or licensing requirement — that prevents expression before it occurs. Prior restraints are the most disfavored form of speech regulation under the First Amendment.
In Near v. Minnesota (1931), the Supreme Court established that prior restraints carry a heavy presumption of unconstitutionality. The Court held that this presumption can be overcome only in exceptional cases, such as troop movements in wartime.
The Pentagon Papers case (New York Times Co. v. United States, 1971) is the leading modern prior restraint case. The Nixon administration attempted to enjoin publication of classified documents about Vietnam decision-making, and the Supreme Court ruled 6-3 that the government had not met the heavy burden required to justify prior restraint.
Prior restraints are contrasted with subsequent punishment — criminal or civil consequences that attach after expression occurs. Both may be unconstitutional, but prior restraints receive the highest level of First Amendment scrutiny.