In New York Times Co. v. Sullivan, 376 U.S. 254 (1964), the United States Supreme Court ruled that the First Amendment limits common-law defamation claims brought by public officials. The Court held that to recover for publication of a defamatory falsehood, a public official must prove that the challenged statement was “of and concerning” the public official plaintiff, that the statement was false, and that the defendant acted with “actual malice.” The Court defined “actual malice” as publication with knowledge that the statement was false or with reckless disregard of whether the statement was false or not.
Later, the Supreme Court extended the standard announced in New York Times Co. v. Sullivan to defamation cases brought by “public figures.” Public figures include individuals who voluntarily inject themselves into public controversy, as well as those who are involuntarily thrust into the limelight, even if only with respect to a particular activity or incident.
A private-figure defamation plaintiff can recover damages based on the defendant’s negligence (or a more speech-protective standard, under the law of some states). In no instance, however, can a private-figure plaintiff recover damages for defamation without a showing of fault amounting to, at least, negligence. Any lesser standard, the Supreme Court concluded, would unduly burden free speech. Gertz v. Robert Welch, Inc., 418 U.S. 323, 347 (1974). And, at least when the speech relates to an issue of public concern, a private-figure plaintiff must bear the burden of proving falsity; the defendant speaker is not obligated to prove the truth of the challenged statements. Philadelphia Newspapers, Inc. v. Hepps, 475 U.S. 767, 768 (1986).