On November 10, 1919, the US Supreme Court ruled in Abrams v. United States that the federal government could criminalize speech if it was of a type tending to bring about harmful results, in this case resistance to the United States war effort. In a powerful dissenting opinion, Justice Oliver Wendell Holmes countered that even during wartime, free speech could only be curtailed when there was clear and "present danger of immediate evil or an intent to bring it about."



Read more on the clear and present danger test by Professor Douglas Linder of the University of Missouri-Kansas City School of Law.