That's because you can't mention any outside contact with AIM in VMK.
They catch you discussing it, it's an instant ban. It's all a part of keeping
VMK safe, and it's part of the rules they list.
That's also why you shouldn't mention the DIS directly as "Message me at
the Dis". That could get someone banned, too.
It's a fair ban if you know they do ban people for that.