I don't support any censorship. But if you were a parent, you might want to think twice about giving your 12 year old free reign on internet porn.
If I were a parent I would have absolutely no problem with my kid accessing porn so long as they had a decent sex education. I don't want to essentially write the same comment twice, but I explain my position reasonably well elsewhere. [2]
[1] http://en.wikipedia.org/wiki/History_of_erotic_depictions
Having a child look at Playboy or those low budget late night tv softcore movies is one thing, or even something more graphic. It's not really about the sex or nudity that's the problem. But imagine children on 4chan. A lot of that stuff can't be healthy.