Of course teenagers know about those things, and creating a separate area doesn't block them from accessing it. My intent was, as Stas correctly pointed out, to organize the site in a way where everybody can find what they're looking for.
Many people are accessing the site from work; most companies have restrictions on the type of content you can browse. This just makes it safer for all the visitors.
P.S: How about a new forum for kids, called Ecstasy?