Anyone else find it difficult to keep silent when professors talk nonsense? I have heard professors spout off on their favorite conspiracy theories, their political views, etc.

Do you speak up, or just let them be?

I have a class on Mondays with a Prof who keeps denying global warming... insisting it's a conspiracy. Also, according to him, our (I'm in the U.S.) legal system has no ties to the British and Roman legal systems... apparently, it's based completely on the Bible.