This is your regularly mandated PSA that the quote about "yelling 'fire' in a crowded theater" comes from Schenck v US, which used that analogy to justify why the government could ban people from protesting the draft in WW1. It is not good law anymore, and has been fully superseded since the Brandenburg v Ohio case which limited the exemption to "imminent lawless action."

Oh well when you put it that way, I guess it's good that kids are dying of measles again.