Kevin, I am third party in this argument, but I agree more on that cheating should be actively investigated, according to how serious this problem is right now. I understand your point that you insist the defender player does not need to provide proof but the one who complain should prove. I actually understand but totally disagree. First we are not a court to be able to sentence anybody, the law rule does not apply. Secondly how can we judge without access to server data? So the only reasonable way is that player himself wash himself clean with evidence. I do not think a legit player will mind to do so. As it is really difficult to believe normal ppl willing to pay so much to upgrade a virtual city wall, there is reasonable ground to raise eyebrow isn't it? The player who is concerned can simply provide any part of the e receipt if your alliance has your own chat group, not difficult or violate privacy.
Of course how to censor is totally your own business, if you think your trust to every member is enough and you believe everyone has a angel spirit it is also fine. Really, nobody wants to interfere your alliance business.
By the way, you respond as having a war in the game is not related to the topic if there is bad apple in your alliance. You may just simply say, I want to be myself and that is the way we run our alliance. Enough is not it?