Good to have mentioned this. The interpretation of "immenent lawless behavior" varies greatly. My wife is an attorney and very recently was on a case where this particular case was cited. While I get your intent in mentioning it, the case is very specific and while Schenck is cited, it does not translate directly to "you can't say fire in a theater," but rather it's far more nuanced. It also doesn't change the fact that the "fire" argument is a lazy slinging of words lacking appropriate nuance.
If we are paraphrasing for the general public I think nuance was thrown out long ago with the bath water. Yelling fire in a crowded movie theater is a paraphrase itself, obviously context matters and always has.
