So... the same flaw we abused to have our older friends buy us booze and cigarettes when we were underage lol I'll still take it. You're not going to get a perfect solution that works all the time. Point is HARM REDUCTION.
REDUCTION.
Not a perfect, flawless, impossible to abuse system. Just a system that helps to make it a bit more difficult and then hope that parents take care of the rest. Some will always still slip through, thems the breaks.
Yeesh I thought I was a nerd but reading some of the replies in this thread it's like some people never even thought how to get access to alcohol and smokes when they were underage. Never even mind porn. We had older friends buy us those magazines too.
I'd do what we're already doing: https://feddit.org/post/26849555/11924777 though this card idea might work too for the sake of data privacy. Not so much for face-to-face privacy, same problem when we got porn on magazines. Let's remember that buying adults goods with the intent to distribute to kids is punishable too. If some 18 year old goes to the store and buys 30 "I'm an adult" cards, there's a good chance the clerk's gonna put a stop to that. After that it becomes effort vs. benefit. Does one really want to go to several different stores to buy multiple cards to sell them for a slight markup? With the threat of getting caught and being charged? There's always the slight embarrassment factor too. Of course adult access could mean a lot of others things than porn too but let's face it: that's what people are going to think, and that's what people are going to think people are going to think.
Again, the magic word is reduction.
There will always be sites that won't comply with any solution, there are p2p sharing methods, TOR and all that. There are always going to be nerdy kids who find their way to forbidden content. But that then becomes easier for parents to keep an eye on. Maybe get the kid off the device more so they simply won't have the opportunity to figure it out. Make sure they only access sites that are in compliance etc. Still not a 100% fool proof solution but again, the point is reduction.