The Schenck case, which created the "yelling fire" line was overturned over 40 years ago:
"In 1969, the Supreme Court's decision in Brandenburg v. Ohio effectively overturned Schenck and any authority the case still carried. There, the Court held that inflammatory speech--and even speech advocating violence by members of the Ku Klux Klan--is protected under the First Amendment, unless the speech "is directed to inciting or producing imminent lawless action and is likely to incite or produce such action""
According to case law and Supreme Court decisions, "Free Speech" is much more absolute than most imagine.
It's also worth noting what, exactly, was the offending speech in that court case, and several related ones (such as https://en.wikipedia.org/wiki/Debs_v._United_States). It was anti-war propaganda, and specifically, calls to resist the draft. The defendants were high-ranking members of the Socialist Party of America.
Principled defense of free speech is often accused of being a slippery slope fallacy, usually by the same people who give "fire in a crowded theater" as a counterpoint. I wonder how many of them are aware that the phrase itself is a historical example of a very real slippery slope.
"In 1969, the Supreme Court's decision in Brandenburg v. Ohio effectively overturned Schenck and any authority the case still carried. There, the Court held that inflammatory speech--and even speech advocating violence by members of the Ku Klux Klan--is protected under the First Amendment, unless the speech "is directed to inciting or producing imminent lawless action and is likely to incite or produce such action""
According to case law and Supreme Court decisions, "Free Speech" is much more absolute than most imagine.
Ref: https://www.theatlantic.com/national/archive/2012/11/its-tim...