In United States constitutional law, false statements of fact are assertions, which are ostensibly facts, that are false. Such statements are not always protected by the First Amendment. Often, this is due to laws against defamation, that is making statements that harm the reputation of another. In those cases, freedom of speech comes into conflict with the right to privacy. Because it is almost impossible for someone to be absolutely sure that what they say (in public) is true, a party who makes a false claim isn't always liable. Whether such speech is protected depends on the situation. The standards of such protection have evolved over time from a body of Supreme Court rulings.
One of the landmark cases that established such standards was New York Times Co. v. Sullivan (1964). In that case, the court ruled that statements about public officials must be given more protection in order to avoid squelching public debate. Similar protections were later expanded to statements about public figures (not just officials), and matters of "public concern" (including those involving private parties). Other examples of false statements of fact that do not receive First Amendment protection include false advertising, as in Lexmark International, Inc. v. Static Control Components, Inc. (2014) and POM Wonderful LLC v. Coca-Cola Co. (2014), and commercial speech that includes misleading statements as in Central Hudson Gas & Electric Corp. v. Public Service Commission (1980).
Section 1001(a) of Title 18 of the United States Code states:
(a) Except as otherwise provided in this section, whoever, in any matter within the jurisdiction of the executive, legislative, or judicial branch of the Government of the United States, knowingly and willfully—
- falsifies, conceals, or covers up by any trick, scheme, or device a material fact;
- makes any materially false, fictitious, or fraudulent statement or representation; or
- makes or uses any false writing or document knowing the same to contain any materially false, fictitious, or fraudulent statement or entry
shall be fined under this title, imprisoned not more than 5 years or, if the offense involves international or domestic terrorism (as defined in section 2331), imprisoned not more than 8 years, or both. If the matter relates to an offense under chapter 109A, 109B, 110, or 117, or section 1591, then the term of imprisonment imposed under this section shall be not more than 8 years.[1]
In upholding a conviction under Section 1001(a) of Title 18 in Bryson v. United States (1969), the Supreme Court stated:
Our legal system provides methods for challenging the Government's right to ask questions—lying is not one of them.[2]