The latest kerfuffle is mega-seller John Grisham* getting indignant because a friend of his was arrested for trying to sign up for a porn site that promised "16-year-old hookers." As many people pointed out, looking at child or teen porn (or for that matter at stolen nude pix) is aiding in the commission of a crime, which is a good argument against doing it.
But I have to wonder how much good is done by dangling temptation and entrapping those who fall for it. I suppose that in theory if we could arrest everyone who wanted to look at the stuff, no one would make it, but that seems awfully indirect. * Grisham's Law states that lawyer novels drive everything else off the bestseller list.