I think that's a question that's a little more technical, if I can speak for Jane, than either of us is qualified to answer.
What I will say is that I'm not certain that there is any power in the world that will prevent teenagers from accessing pornography. I don't mean to be flippant with that. Certainly, there are tools that can be used, and I know there are tools that are being used. This is being discussed in the U.K. right now. I believe legislation has just been passed on that very topic. There's a lot of discussion going on, in terms of Internet safety in the U.K., about how to actually make this work and whether it is worth doing.
Certainly, there are ways of identifying or guessing people's ages. That's a big part of what algorithms do, because part of your profile is how old you are, but there are a lot of technical challenges to something like that. Like all other blocking or filtering tools, it's never going to be 100% effective, and there's a very good chance that it will result in a lot of false positives, like most blocking and filtering tools do. At the very best, it would be a complement to a digital and media literacy approach to pornography.