Right, exactly. That's how you know it is a bad rule, because it is impossible to define appropriate exceptions.
Going back, I think the rule came about through Matt's misinterpretation of an arguably good rule, being that you shouldn't be allowed to post someone's personal identifying information (real name, address, phone number, etc.).
All that said, I just remembered that I already knocked my head against this wall almost four years ago. So, I'll just leave well enough alone.