It looks like a case of a new problem being addressed with old laws. Children photographing themselves is dumb and dangerous, though realistically, it's certainly less dangerous than underage drinking and driving, which will actually kill kids.
What exactly is the fear? I guess there's a small likelihood that creepy perverts will find the photos and be be enticed to harm the actual children, but how often does that really happen? The greatest danger is that being sexual online endangers a child's future. In the future naked pix of yourself on the net isn't going to be nearly as scandalous as it is now, but it's still reasonable for the law to take steps to protect a minor from permanent consequences of youthful indiscretion.
However, few things destroy a person's future more completely than a felony sex offender conviction. We may need new laws that address the fact that children photographing themselves is very different from adults photographing children, and bring us back to the supposed intent, to protect children.