How have Congress and the courts justified placing limits on the freedom of speech?

3 answers

http://www.freedomforum.org/packages/first/curricula/educationforfreedom/supportpages/l04-limitsfreedomspeech.htm

http://ever-increasing-entropy.blogspot.com/2009/12/legitimate-limitations-on-freedom-of.html
as always, just what i needed. thank you very much.
You're very welcome.