PKOK Suggestion -- Allies list
My suggestion is allow each person to designate a list of allies -- individuals or clans that any attack will have to accept before they can attack you. When someone accepts you, the mud will list everyone on your allies list and warn that your allies will also be accepted. At that point, the attacker has the option of confirming or declining the accept command. ("All" would not be allowed on an allies list.)
This would mean that nobody would be able to ignore attacks from your friends or clanmates and this loophole would be closed.