Brandenburg Vs Ohio
Brandenburg v. Ohio, 395 U.S. 444 (1969), was a landmark decision of the United States Supreme Court interpreting the First Amendment to the U.S. Constitution.
The Court held that the government cannot punish inflammatory speech unless that speech is "directed to inciting or producing imminent lawless action and is likely to incite or produce such action".
Specifically, the Court struck down Ohio's criminal syndicalism statute, because that statute broadly prohibited the mere advocacy of violence. In the process, Whitney v. California (1927) was explicitly overruled, and Schenck v. United States (1919), Abrams v. United States (1919), Gitlow v. New York (1925), and Dennis v. United States (1951), were effectively overturned.