Well, I never saw a single porn magazine when I was growing up; not at my house, and not at my friend's houses. The one time I did see a pornographic video was a Japanese anime film that one of our neighbors was watching while I played with her daughter. I was shocked, and left the house--I think I was about 13. I never told my parents.
So I understand that porn has always existed, and has always been accessible to some extent. However, it has NEVER been as accessible as it is now, and yes, there are free sites that offer streaming porn. I won't list the link here, but I'm aware of at least one in particular.
I DO agree that online, you pretty much get what you go searching for. However, I would like it if my children couldn't access it even if they went searching for it. We have good filters on their computers, but as they get older, that interferes with research and access to some sites they actually need, so I sometimes have to turn the filters off. *sigh*
I realize that at some point they will probably be exposed to it, but I'm not happy about that, and I certainly don't view it as some sort of *harmless* part of growing up. Hard core and fetish pornography is a twisted representation of sex between a married couple, and further, I think sexuality should be explored in the marital bed; not online or in magazines with pictures and videos of someone besides your spouse. I am completely against couples using pornographic images and videos to "spice up" their love life, and it always shocks me when Christians find these types of things acceptable.
But, I digress.
I'm suspicious of the government's motives in this as well, because we certainly don't want them filtering out other sites that they deem politically incorrect, etc. Hoovie's right; if private companies would handle the opt-in process, that would be a superior option.
That said, I'm in support of the idea.