Defamation is the intentional communication of a falsehood about a person, to someone other than that person, that injures the person’s reputation. Libel is written defamation; slander is oral defamation. Online defamation is generally considered to be libel.
The injured person may sue and recover damages under state law, unless state law makes the defamation privileged (for example, a statement made in a judicial, legislative, executive, or administrative proceeding is ordinarily privileged). Being required to pay damages for a defamatory statement restricts one’s freedom of speech; defamation, therefore, constitutes an exception to the First Amendment.
First Amendment limitations
The U.S. Supreme Court has granted limited First Amendment protection to defamation. The Court has held that public officials and public figures may not recover damages for defamation unless they prove, with “convincing clarity,” that the defamatory statement was made with “‘actual malice’ — that is, with knowledge that it was false or with reckless disregard of whether it was false or not.”
The Court has also held that a private figure who sues a media defendant for defamation may not recover without some showing of fault, although not necessarily of actual malice (unless the relevant state law requires it). However, if a defamatory falsehood involves a matter of public concern, then even a private figure must show actual malice in order to recover presumed damages (i.e., not actual financial damages) or punitive damages.