Here is the intro from Kent Scheidegger of CrimeandConsequences blog.
To refute the notion that freedom of speech or the press is absolute, a
common device is to cite a hypothetical of spoken or written words that
everyone with sense would agree can be prohibited. The most famous is
Justice Holmes's example in Schenk v. United States, 249 U.S. 47, 52 (1919), "The
most stringent protection of free speech would not protect a man in
falsely shouting fire in a theatre and causing a panic." Another
classic is that of Chief Justice Hughes in Near v. Minnesota, 283 U.S. 697, 716 (1931), "No one would question but that a government
might prevent … the
publication of the sailing dates of transports or the number and
location of troops."
common device is to cite a hypothetical of spoken or written words that
everyone with sense would agree can be prohibited. The most famous is
Justice Holmes's example in Schenk v. United States, 249 U.S. 47, 52 (1919), "The
most stringent protection of free speech would not protect a man in
falsely shouting fire in a theatre and causing a panic." Another
classic is that of Chief Justice Hughes in Near v. Minnesota, 283 U.S. 697, 716 (1931), "No one would question but that a government
might prevent … the
publication of the sailing dates of transports or the number and
location of troops."
Now read, John Christoffersen, Ex-sailor sentenced to 10 years in terror case, Washington Post, 3 April 2009.