The sword of free speech cuts both ways. You think they are "nutjobs" but you do not have the right to tell others not to listen to them. You are fully within your rights to not associate with them or their content. They may think your side are the "nutjobs" but they dont have the right to silence you either. Therefore anyone can post anything they want and it is up to the individual to decide what content they will consume and which content they will not associate with.