I'm not necessarily advocating it but I can understand it and see those people as reasonable somewhat.
I mean think about it, you as a Christian have two big commandments the 2nd most important is to love your neighbor as you love yourself. But the first and most important is to love god with all you heart, mind, and soul. So imagine that someone says some truly vile disgusting things about your wife, will you support their right to free speech, or is their a chance you will get violent? Now remember you are suppose to love God more than your wife and children. So if you hold the belief that violence is NEVER ok in the case of mere words, you are being consistent. BUT if you are willing to get violent if someone insults your wife, or your parents, or burns something you hold important like your nation's flag, but then you do nothing if someone does something like piss Christ, or insults Jesus. Then you should look at yourself. Because the insult to religion should have a stronger response than to things that are merely personal.