I'm not about to tell all about how I track minors on the site. There are various tools that I use to determine whether or not someone is a minor. There are other tools that I use that access information in our database.
Just know this: We DO track usage on our site. I'm not about to divulge what sorts of files we use to do that tracking either. If you are a minor on this site reading and/or writing adult material, chances are high that you will eventually be caught, even with over 6,000 members.
And, no, none of the other Admins are going to divulge that information either... sorry!
~~Wiccan~~