A group called Blogger Power is calling for an end to "free tours" on porn sites. Their official statement:
Please require a password-protected login before allowing even free access to explicit adult content. We understand that selling porn is your business and we respect your right to make a legal living. But understand our legitimate concerns and work with us. You already have the “warning adult content” on your websites. Yet kids, who are not legal customers of your product, ignore the warning. So to prevent them from having direct access to explicit images, texts and sounds, the simplest way is to have a password-protected login. No more “free tours” before a visitor supplies basic information.
I agree that porn is a major problem, though I can't completely agree with their approach. What's to keep children from creating an account? I'd suggest an ICANN policy (a law would only apply to sites hosted in the US) requiring pornography to be restricted to a .xxx domain. This would allow for better filtering of adult content. A person could be able to ask their ISP to block all .xxx domains kind of like they can ask their phone company to block 1-900 numbers or set their browser to display a warning before displaying .xxx pages.
At this point though it's clear that something needs done. If you still need proof look no further than the case of the substitute teacher facing jail time (alternate story) over an unwanted porn pop-up.
Update (3:20 P.M. 2/25): I agree that password logins would protect young children and should be implemented. I still think it should be used in combination with some form of the .xxx domain approach.