Actually the minimum age for employment in U.S. is 14 years (for non-agricultural jobs), and in Australia, where NightCafe is seated, it's 15 years. Unfortunately, as far as I can tell, NightCafe seems to be bending the term "Not-Safe-For-Work" at their own will, perhaps in order to manipulate and censor content that might reflect values they don't themselves agree on? Of course it's implied that you'll have to be old enough to actually have a job (Work) before you're really meant to be part of the consideration. The term is not called "Not-Appropriate-For-Kids", that would be a different term, and there would be no problem in making such a term, except perhaps for the fact that traditionally in western societies it would be up to the parents to decide. NightCafe seems to imply that many contemporary parents do a bad job at parenting, I'm not sure if there's actually evidence to back up such a claim?