Libel and slander are legal claims for false statements of fact about a person that are printed, broadcast, spoken or otherwise communicated to others. Libel refers to statements in written or other permanent form, while slander refers to verbal statements and gestures. The term defamation encompasses both libel and slander.
In order for the person about whom a statement is made to recover for libel, the false statement must be defamatory, meaning that it actually harms the reputation of the other person, as opposed to being merely insulting or offensive.
The defamatory statement must also have been made with fault. The extent of the fault depends primarily on the status of the plaintiff. Public figures, such as government officials, celebrities, well-known individuals, and people involved in specific public controversies, are required to prove actual malice, a legal term which means the defendant knew his statement was false or recklessly disregarded the truth or falsity of his statement. In general, private individuals must show only that the defendant was negligent, that he failed to act with due care in the situation.
A defamation claim will fail if any of these elements are not met.
The primary defenses to a defamation claim are that the statements are true, are statements of opinion or otherwise not statements of fact, or are privileged.
Truth and opinion are complete defenses to a defamation claim. In addition, some defamatory statements may be protected by privilege, meaning that in certain circumstances the interest in communicating a statement outweighs the interest in protecting reputation. For example, many jurisdictions recognize a privilege for media reports of government and judicial proceedings, and for reports of misconduct to the proper authorities.
A successful defamation plaintiff may be entitled to a jury award of money damages. In some instances, the plaintiff may also be awarded punitive damages for particularly reprehensible conduct. The parties to the claim are entitled to appeal and cases are carefully scrutinized on review to protect the defendant?s First Amendment rights.
Defamation claims can be brought by living persons and legal entities such as corporations, unincorporated businesses, associations and unions that are considered "persons" under the law. Governmental entities cannot maintain actions for libel or slander, although a government official can bring suit for statements directed at them individually.
Libel and slander are civil claims, but about half the states recognize an action for criminal defamation. Prosecutions are rare, especially against the media.
Under the American federal law system, defamation claims are governed by state law, subject only to the limitations imposed by the free speech and press provisions of the First Amendment to the U.S. Constitution. While the elements of defamation are practically identical throughout the country, because defamation is a matter of state law there are important differences on substantive and procedural details of the claim in the separate jurisdictions. For example, states can, and several do, provide heightened protections against defamation beyond those required by the First Amendment.
EDIT: Citation:
http://www.ldrc.com/LDRC_Info/libelfaqs.html