This kind of goes back to what I was saying about the media. The media's role isn't to inform us. What do you think is more conducive to selling the most amount of advertising: the world is an ambiguous place where even the legal system doesn't have the answers, ot the world is a consistent, comfortable place with absolute right and wrong which always correlates with the law? There is a reason why when you watch "To Catch a Predator" you don't hear about how many people they "catch" but do not convict. There is no debate on Dateline if what they are doing is actually ethical, if there is any way you can actually prove what these guys "believed" or their "motives" as if there is any evidence which can peer inside the heads of others. Comfort sells; we're comforted by some outrage, provided that we know that there is some hope for order, some moral code which we all can rely on. Outrage is comfortable because of this.
But what we can't deal with is that under some circumstances that moral code breaks down, that the very things we morally value conflict with other moral values - freedom of speech with speech we cannot get behind, the mere thought that someone's getting off on Sally Mann is pretty revolting. Suddenly outrage becomes fear, we loose that sense of empowerment of being right in our outrage - it's no longer something positive, but rather the realization of the limits of society, and that society cannot protect us from that which makes us uncomfortable, that we have no right to being cozy and coddled.
This realization doesn't sell advertising, so you're not going to see documentaries on the ambiguity of child pornography on Dateline, for the same reasons you're not going to see a serious discussion on if "To Catch a Predator" is ethical. It's better for advertisers to feel right than wonder if we're wrong.