I think that we live in a society, where the Internet can be a fascinating place, but a dangerous one.
Parents are constantly being warned to keep a watch on their children, while they are on the Internet.
And Internet providers are constantly being asked to be more vigilant, regarding what is allowed to be aired.
I think that it is morally right, for site-owners to act as responsibly as possible.
So, yes, even though kids will get around the rules by lying, it is still right for site-owners to have those rules.
However, there are some sites which are very obviously aimed at children.
I think that the 'parakeets' section of this site may come into this category.
Maybe it would be possible to have 'parent & child' membership for such areas?
I think that the conversation in the 'general' section can be of such an adult nature, at times, that it really isn't suitable for children.
Age can affect conversations.
When I first joined the site, I was wary of discussing some matters, even with under 18's.
Also, some members have become very irritated, after debating a point with 'a fellow adult', only to find that the entrenched views were coming from a thirteen-year-old.
See:
Under 18s
http://www.wineintro.com/forum/ubbthreads.php/ubb/showflat/Number/87859Age restriction.
http://www.wineintro.com/forum/ubbthreads.php/ubb/showflat/Number/120042