Rumor vs Reality

Hate speech is protected by the First Amendment. The Supreme Court upheld this protection again in Matal v. Tam 2017. However, speech meant to cause violence, false advertising, slander or libel can be banned by the government. If speech crosses these lines, it is not protected.
References
LawShelf: Freedom of Speech Exceptions: Categories of Speech NOT Protected
Justia US Supreme Court: Justia Opinion Summary and Annotations