Lock Clan join once a war is declared
We just caught a snooper account. After a war was declared, a new member joined the clan, used the log to see what plans were made, and checked war base troop loading. He ran his mouth at school not realizing that by a very lucky chance that his clan was warring our clan and our member heard him talking then watched him log into his spoof account and show others what he was doing with it.
My suggestion is once a war is declared, no new members can join the clan until the war is completed, this eliminates yet another loophole on why to keep 2 or more accounts.