During World War I, Congress
passed the Espionage Act of 1917,
which basically made it a crime to make statements that would interfere
with 'military success' or obstruct 'recruiting and enlistment' into the
military, when the US was at war.
Schenck (a Socialist!) printed
a document encouraging people to become draft-dodgers and to press for a
repeal of the draft. He was arrested and charged with violating the Espionage
Act.
The Trial Court found Schenck
guilty and sentenced him to six months in prison. He appealed.
Schenck argued that the Espionage
Act was unconstitutional because it
interfered with his 1st Amendment guarantee of freedom of speech.
The US Supreme Court upheld
the conviction.
The US Supreme Court agreed
that Schenck's document would be protected by free speech in general.
However, the Court found
that because there was a war going on, and because Schenck's document
could create a 'clear and present danger', Congress was within their
power to prevent Schenck from expressing his beliefs.
The Court likened Schenck's
actions to "shouting 'fire' in a crowded theater."
This case defined the clear
and present danger exception to freedom
of speech, which says that a law is
constitutional if it can be shown that the language it prohibits poses a
"clear and present danger."
"Clear and present
danger" was later limited by Brandenburg
v. Ohio (395 U.S. 444 (1969)), to situations where speech
would provoke an "imminent lawless action."
This was one of the first
cases in which the US Supreme Court dealt with the 1st
Amendment. Until this point, there
was not a lot of litigation on the subject.
This was the first case that
suggested that the 1st Amendment goes beyond prior restraint and in fact extends to
subsequent punishment.
A prior restraint is something that prevents speech from
occurring, like forcing someone to get a license before printing a
paper.
Alternately, there are laws
that punish speech after it has occurred, like penalties for libel or
slander. (aka subsequent punishment)
The difference is that if
there is an injunction, you can still be punished for violating the
injunction, even if it is later determined that the speech was protected
by the 1st Amendment.