How do BOTS get away with promoting their sites in Yahoo Chat when there are minors in the chat rooms?

If you look at the chat room rules, you'll see that minors are not supposed to be in the rooms...at least that's the way it was when I began going to chat two years ago. Of course, minors CAN get in, but there was a note when entering chat, that anyone under 18 was not supposed to be there.