In the United States, some categories of speech are not protected by the First Amendment. According to the Supreme Court of the United States, the U.S. Constitution protects free speech while allowing limitations on certain categories of speech.[1]
Categories of speech that are given lesser or no protection by the First Amendment (and therefore may be restricted) include obscenity, fraud, child pornography, speech integral to illegal conduct, speech that incites imminent lawless action, speech that violates intellectual property law, true threats, false statements of fact, and commercial speech such as advertising. Defamation that causes harm to reputation is a tort and also a category which is not protected as free speech.
Hate speech is not a general exception to First Amendment protection.[2][3][4][5][6] Per Wisconsin v. Mitchell, hate crime sentence enhancements do not violate First Amendment protections because they do not criminalize speech itself, but rather use speech as evidence of motivation, which is constitutionally permissible.[7]
Along with communicative restrictions, less protection is afforded to uninhibited speech when the government acts as subsidizer or speaker, is an employer, controls education, or regulates the mail, airwaves, legal bar, military, prisons, and immigration.