Depending on how the forums shape up with respect to content and images I would like to suggest adding COPPA. I just registered as an 11 year old under "TestAge" (please delete, Rand or Dread) with not only no "sorry, too young" but also no information about site content, or any warnings, etc.
It would suck to see the site get into trouble with the law because t's weren't crossed and i's not dotted and some 10 year old is found on the site by mom and dad who then pull a "fo shame, omg. honey call the lawyer".
In fact, I strongly recommend looking into this and getting it done.