Asked you for the law, not cultural arguments or view points.
I have dinner shortly, i can only copy pasty sorry
"Under U.S. law, the First Amendment protects most speech, but there are well-established exceptions where it does not apply. These include:
Incitement to imminent lawless action – Speech intended to and likely to cause immediate illegal activity (Brandenburg v. Ohio, 1969).
True threats – Direct threats of violence against individuals or groups (Virginia v. Black, 2003).
Obscenity – Material that meets the three-part test in Miller v. California (1973) and lacks serious literary, artistic, political, or scientific value.
Child pornography – Criminalized regardless of its content or intent (New York v. Ferber, 1982).
Defamation – False statements that harm a person's reputation (New York Times Co. v. Sullivan, 1964; with higher standards for public figures).
Speech integral to criminal conduct – For example, aiding or soliciting crimes.
These are legal limitations recognized by U.S. courts, not just opinions."