Charles Schenck was arrested for violating the Espionage Act of 1917 by mailing pamphlets to men that had been drafted saying the government had no right to send them to kill people in other countries. Schenck said his First Amendment rights had been violated. The Supreme Court decided against Schenck, and established the “clear and present danger test.” The opinion written by Justice Oliver Wendell Holmes stated that “the most stringent protection of free speech would not protect a man in falsely shouting fire in a theater and causing a panic.” The question, he wrote, “is whether the words used are used in such circumstances and are of such a nature as to create a clear and present danger that they will bring about the substantive evils that Congress has a right to prevent." Schenck’s act created a clear and present danger for the ability of the government to fight the war. His words, though tolerable in peacetime, were not protected in times of war.
Read the decision: http://www.thisnation.com/library/schenck.html
This case, decided by the Supreme Court only eight months after its decision in Schenck, involved four political radicals who were arrested for distributing "seditious" leaflets by throwing them out of a third floor window in New York City. By 7-2, the justices decided that the free speech rights of the accused had not been violated by their arrest. The case is important for the eloquent dissent written by Justice Oliver Wendell Holmes, who modified his own "clear and present danger" test to say speech should be protected unless immediate danger to the government was at hand. He called the leaflets involved in this case "silly" and said they did not represent such a danger and should therefore be protected.
Benjamin Gitlow was a socialist who was arrested and prosecuted for distributing copies of “left wing manifestos” that called for the establishment of socialism through strikes and other actions. Gitlow was prosecuted for “criminal anarchy” under a
state law that punished advocating the overthrow of the government through force. Gitlow argued that he was innocent due to the fact that the manifesto caused no violent action and so his speech should be protected by the First Amendment. The decision represents the first time the Supreme Court ruled that the First Amendment does apply to the states, not just to the federal government. But it did not uphold Gitlow’s First Amendment rights. Instead, it said that a state has the authority to forbid any speech and publication if they have a tendency to result in action dangerous to public security, but do not create a “clear and present danger.” This is known as the “dangerous tendency” test.
Read the decision: http://www.oyez.org/cases/1901-1939/1922/1922_19/