I once shared an apartment with Evil, and that experience has given me a rich store of anecdotes I can use in teaching. The most common one I use explains the difference between what you have the right to do, and what you ought to do.
Evil was on the phone with his mother, when he found out that she was selling her car in the paper. Evil did not like this. Evil thought that his mother should give him her old car for free. When she said that she needed the money for the down payment on the new car, Evil became quite mad. Then he called his mother a rude name that rhymes with “runt” (*)
Now it is clear that Evil had a right to call his own mother a rude name that rhymes with “runt.” Any government that tried to prescribe how you should address your mother is absurdly intrusive. I was not entitled to use any force to prevent Evil from calling his own mother a rude name that rhymes with “runt”, other than to simply say “Dude, I can’t believe you called your own mother a rude name that rhymes with ‘runt’” In fact, I didn’t even do that, because by this point I was so used to Evil’s evil that I didn’t even bother.
Nevertheless it was wrong for Evil to call his own mother a rude name that rhymes with “runt.” And even though I support Evil’s right to call his own mother such names, reminding the world of this fact was not the first thing on my mind when I heard evil call his own mother a rude name that rhymes with “runt.” If I were still speaking to him, I would have focussed all my energy on getting him to apologize, and wouldn't really think about the free speech issue at all.
I certainly would not phone Evil’s mother myself and call her a rude name that rhymes with “runt”, as an act of solidarity in support of Evil’s right to free speech.
Now suppose that Evil’s mother was really sensitive about being called a rude name that rhymes with “runt.” So sensitive, in fact, that when she is insulted this way, she completely flips out, setting fire to her house, and marching in the street protesting the injustice of the rude name that rhymes with “runt.” Well then I really wouldn’t call her on the phone and call her a rude name that rhymes with “runt” simply to show my support for free speech. Especially if I thought that this sensitivity was actually the product of years of being called rude names by her vicious, ungrateful child.
While I'm on this topic, I would also like to endorse Majikthise' comments on the Danish cartoons.
(*) when I tell this story in class, I always say “a rude name that rhymes with ‘runt’, because I’m trying to cut down on swearing in class. Once I just said that he called her a rude name, but my students assumed it was a rude name that rhymes with “rich”, and couldn’t see what the big deal was. Also, I just like saying “a rude name that rhymes with ‘runt’”