Bill Stewart writes:
Peter Zenger was a publisher in New York during colonial times. He was arrested for publishing Bad Things about the King, which was illegal. His trial was helped reinforce important legal precedents for preserving our freedoms - the facts weren't particularly in dispute (he had published the pamphlets, and they did say things the King didn't like), but the jury found him innocent because they thought the law was bad, and juries under the common law have always had the right to judge the law as well as the facts, no matter what the judge says.
John Peter Zenger, actually. And it was comments about the colonial governor, not about the king. The Zenger case is commonly taken to be a precedent both for press freedom and for jury nullification. --Mike