The First Amendment does not apply to advocating imminent lawless behavior.

Hess v. Indiana, 414 U.S. 105 (1973):

Under our decisions, "the constitutional guarantees of free speech and free press do not permit a State to forbid or proscribe advocacy of the use of force or of law violation except where such advocacy is directed to inciting or producing imminent lawless action and is likely to incite or produce such action." Brandenburg v. Ohio, 395 U.S. 444, 447 (1969). (Emphasis added.) See also Terminiello v. Chicago, 337 U.S., at 4 . Since the uncontroverted evidence showed that Hess' statement was not directed to any person or group of persons, it [414 U.S. 105, 109]   cannot be said that he was advocating, in the normal sense, any action. And since there was no evidence, or rational inference from the import of the language, that his words were intended to produce, and likely to produce, imminent disorder, those words could not be punished by the State on the ground that they had "a `tendency to lead to violence.'" ___ Ind., at ___, 297 N. E. 2d, at 415.

Fighting Words: The First Amendment does not protect "fighting words."

Cohen v. California, 403 U.S. 15 (1971):

This Court has also held that the States are free to ban the simple use, without a demonstration of additional justifying circumstances, of so-called "fighting words," those personally abusive epithets which, when addressed to the ordinary citizen, are, as a matter of common knowledge, inherently likely to provoke violent reaction. Chaplinsky v. New Hampshire, 315 U.S. 568 (1942).

Obscenity: Obscenity may be punished.

Alexander v. United States, 509 U.S.544 (1993):

We have in the past rejected First Amendment challenges to statutes that impose severe prison sentences and fines as punishment for obscenity offenses. See, e.g., Ginzburg v. United States, 383 U.S. 463, 464 -465, n. 2 (1966); Smith v. United States, 431 U.S. 291, 296 , n. 3 (1977); Fort Wayne Books, 489 U.S., at 59 , n. 8.

Defamation: A plaintiff may recover damages for defamation, but with limitations.

New York Times v. Sullivan, 376 U.S. 254 (1964):

Respondent relies heavily, as did the Alabama courts, on statements of this Court to the effect that the Constitution does not protect libelous publications. 6 Those statements do not foreclose our inquiry here. None of the cases sustained the use of libel laws to impose sanctions upon expression critical of the official conduct of public officials. The dictum in Pennekamp v. Florida, 328 U.S. 331, 348 -349, that "when the statements amount to defamation, a judge has such remedy in damages for libel as do other public servants," implied no view as to what remedy might constitutionally be afforded to public officials. In Beauharnais v. Illinois, 343 U.S. 250 , the Court sustained an Illinois criminal libel statute as applied to a publication held to be both defamatory of a racial group and "liable to cause violence and disorder." But the Court was careful to note that it "retains and exercises authority to nullify action which encroaches on freedom of utterance under the guise of punishing libel"; for "public men, are, as it were, public property," and "discussion cannot be denied and the right, as well as the duty, of criticism must not be stifled." Id., at 263-264, and n. 18. In the only previous case that did present the question of constitutional limitations upon the power to award damages for libel of a public official, the Court was equally divided and the question was not decided. Schenectady Union Pub. Co. v. Sweeney, 316 U.S. 642 . [376 U.S. 254, 269]   In deciding the question now, we are compelled by neither precedent nor policy to give any more weight to the epithet "libel" than we have to other "mere labels" of state law. N. A. A. C. P. v. Button, 371 U.S. 415, 429 . Like insurrection, 7 contempt, 8 advocacy of unlawful acts, 9 breach of the peace, 10 obscenity, 11 solicitation of legal business, 12 and the various other formulae for the repression of expression that have been challenged in this court, libel can claim no talismanic immunity from constitutional limitations. It must be measured by standards that satisfy the First Amendment.