Based on the example of Ed Rosenthal there's something about freedom of speech that's puzzling me:
According to the article and to what I've read about the case, a defendant in court has been denied the right to even say that what he did was legal under state law.
In my personal opinion this looks like an outright violation of freedom of speech, because I can't think of any reason why a defendant should be in any way restricted as to what he is allowed to say. Being allowed to say anything doesn't force anyone (judge/juror) to believe that it's true and obviously there're good reasons for example to force witnesses to only say the truth, because their freedom of speech quickly conflicts with the defendant's right for a fair trial should they be allowed to lie.
I'd like to know the explanation for this as I'm sure there is one, though it's not obvious for an "outsider" like me. Besides that, I wonder if this has ever been challenged in court.