Speech about sex and sexuality receives protection under the First Amendment, and this protection extends to many forms of pornography. However, certain types of sexually explicit expression are not protected.
Obscenity is not protected by the First Amendment. Obscenity is a narrow category of unprotected expression that meets all of the following criteria: (a) the average person, applying contemporary community standards, would find that the work, taken as a whole, appeals to the prurient interest; (b) the work depicts or describes, in a patently offensive way, sexual conduct specifically defined by the applicable state law; and (c) the work, taken as a whole, lacks serious literary, artistic, political or scientific value.
The government can also restrict minors’ access to pornography, and criminal statutes that prohibit adults from exposing minors to pornography have been ruled constitutional. Additionally, child pornography is not protected by the First Amendment.
Sexual harassment, discussed elsewhere, is a separate category that is outside of First Amendment protection.