Tight V. Formation

Let's see how many people show up at the bottom after I post this... haha!

I know many of you are parents and maybe some of you have been through this... I'm having a difficult time addressing the subject with my son.
Last time he was out visiting, he spent the day at home while I worked. He is 12 and I've come to the conclusion that I can trust him to take care of himself and not burn the apartment down or anything crazy like that. He's been flying by himself for years now so I have no reason to believe that he is incompetent in those regards.
However...
As I would come home some evenings, I would log onto our computer and find porn sites in the address bar drop down. I was shattered...here, my cute little genious of a kid, had somehow discovered the world of internet porn. It was nothing hardcore..more of sites where you could look at celebreties boobs and stuff like that. However, I've viewed my share of internet porn and know that it's always just a few clicks away from the hardcore stuff.
God, in a way, I envy this generation. They have it so easy..it's so accessable. When I was growing up, we had to smuggle Penthouses into our Trapper Keepers at the local convienence store, then find a safe place to hide them at home. Somehow, they always disappeared a few days after going between the matress and the boxspring. And that was the hassle one had to go through for mags... for video, I remember spending an hour once trying to figure out my dad's lock-out code on the cable box. Eventually, I gave up and ended up watching the scrambled porn channels..which rarely would offer a glimpse of a boob or ass between the noise and squiggly lines. It was tough back in those days. Not so much now. Kids can enter any sex term into Google and come up with millions of choices.
So I'm trying to decide how to handle this when he comes out again this year. Do I get cybersurfer or netnanny and block his access? He's only doing something I would have done at his age. Do I turn a blind eye? Is this enabling him? Honestly, I know some see beating off or viewing pornography as a sin.. I don't go there... I think it's all natural until someone's thoughts get perverted and go places they shouldn't.