COPPA, Children's Online Privacy Protection Act, as I must say, people are taking it too seriously. If you're an admin on a certain wiki and finds an underaged user there lurking around, you can block them.

Underaged users can easily fake their age, and there's nothing we can do about it. For example, an 11 year old signs up for Wikia and when other wikians ask about his age, he denies that he's only eleven and claims that he is sixteen. 

I think we should start looking at the maturity of others instead of their age. Age is just a number, isn't it? I'm not underaged, but there are some users who are and they easily lie about it. In my opinion, they shouldn't be liars but can we please accept them if they're mature?