A gag order is a court order that prohibits the attorneys, parties, or witnesses in a pending lawsuit or criminal prosecution from talking about the case to the public. The order is usually directed at the attorneys, witnesses, and parties before the court not to publicly discuss the facts of a case. The purpose of a gag order is to prevent prejudice due to pre-trial publicity which would influence potential jurors. Gag orders may be necessary to protect other valuable rights under the Constitution, such as the right to a fair trial. However, a court will scrutinize any gag order under the right of free expression, protected by the First Amendment, and applies a heavy presumption against its constitutional validity, as with any prior restraint. If a gag order is defied, it can be treated as a matter of contempt of court.