How do you catch a spy in alliance?

This game has no options for catching a spy (wish it did). Usually a player around level 20+ gets bored playing the game and just wants to kill his current alliance, so he starts many another game players using different emails and harasses the alliance until he gets board or the alliance breaks up, usually he gets bored and moves on or runs out of money and doesn’t think it’s worth the cash. The only thing you can do, is keep your resources at a low level so the spy doesn’t get much and move your base around so you are hard to find..