Complex sentence: This is a U.S. federal law, but there is no penalty for failure to comply with it and the U.S. Supreme Court has ruled that punitive enforcement would conflict with the First Amendment right to freedom of speech.
Split into simpler sentences: This is a U.S. federal law, but there is no penalty for failure to comply with it. In fact, the U.S. Supreme Court has ruled that punitive enforcement would conflict with the First Amendment right to freedom of speech.