They have freedom of speech. As do we all. They don't forfeit their freedoms once they do that. That behavior is simply not covered under the umbrella of "free speech." Just like shouting fire in a crowded theater is not covered. Or in England, fighting words are not covered.

You are being defensive and biased, by the way. When you are looking at a philosophical question (or any question really), you want to step back from your emotions. Think rationally about the topic. Acknowledge your emotions, because they have indications as well, but don't let yourself be ruled by them. Sometimes emotions can cause to make mistakes. Like the saying about fighting when you're angry. The angry man always loses in a fight. Because his opponent can easily predict his moves, and he also completely loses control. So his swings become wild and erratic. Rather than controlled and strong and striking true and on target.