I don't think it's exactly childish of them... there was a time when we atheists, for the very reason of BEING atheists, were burned at the stake and tortured for our... lack of belief. That's pretty damn childish, if you ask me. When you're afraid of something, don't confront it, but destroy it.
Do I think the Bible is dangerous? Absolutely. Would I equate it to porn? Not exactly. I have no beef with porn or the porn industry, and (someone above mentioned that porn is generally considered exploitation of women) most people enjoy what they do. It's not really hurting anyone, and most contemporary porn films show women as superior to men; not to mention they're really quite comical (I remember one that involved a comic book character coming to life, and a scientist was talking about the impossibility of it, stating examples such as "Bush's reelection?"
Anyway, what people have to understand is that one of the major things that separate us atheists from the high-strung religious people is a sense of humor. Don't get me wrong, I remember priests from my childhood who cracked jokes, but by and large, religion is non-humor oriented, especially the fundamentalist approach. And it's well known that people with no sense of humor are easily offended. They could have equated the Bible to a British sit-com, and it still would be controversial.
Atheism is growing steadily, a fact I'm incredibly happy about. However, we're still a minority. I was talking to a girl a while ago at work who is near-fundamentalist, and she told me that even though I'm a decent person and do nothing bad, the very fact that I don't accept Jesus as my lord and savior gives me a one-way ticket to Hell. That's not very comforting to me, especially knowing that these people can, and did, run the country, and it convinced me that religion isn't as interested in people being good and moral as it is for people to conform to their ideal belief.
And people call these kids childish for what they did? Get real.
Penn & Teller once said that "there's no easier road to atheist than to read the Bible front to back". I agree with this statement. If you belonged to a social group that was responsible for hatred, death, war and overall bigotry, would you be proud? Surely the KKK had group meetings with good food and people enjoying themselves. The Nazis too. But let's not fight against them, let's fight against the comedians that poke fun at them, let's damn the people who speak against them, and let's just kill everyone who doesn't agree with them.
Oh wait... they tried that?
Try wearing a swastika in public (it represents a statement of beliefs, doesn't it?). Why is it that wearing a crucifix is any more redeeming?