 Speech rights were expanded significantly in a series of 20th- and 21st-century court decisions that protected various forms of political speech, anonymous speech, campaign financing, pornography, and school speech; these rulings also defined a series of exceptions to First Amendment protections.The Supreme Court overturned English common law precedent to increase the burden of proof for libel suits, most notably in "New York Times Co. v. Sullivan" (1964).Commercial speech is less protected by the First Amendment than political speech, and is therefore subject to greater regulation.