Long Answer: If you admit to being underage, another user can report you to Ferret, who will ban you. For example, about a month ago, red303 was perma-banned for being underage.
Yes, although if you were twelve when you joined the site, then admitted that you were twelve after your thirteenth birthday then the moderators can do nothing.
But why would underage users say that they are underage? I don't get the point. Someone please help me?
1) They're kids. 2) They're stupid. 3) They don't think someone will tell. 4) They don't realize that everyone can read their posts. 5) They never read the rules and don't know they need to be 13+
ArmorGames enforces the 13+ policy due to Federal Law. If we know you are 12-, we must act upon the account. If we are accused of allowing an underaged user with an account and we didn't know previously, we are protected with a "well, the T&C does state that you have to be 13+ to access this site..." as a first line of defense.