Some examples to illustrate my point, only looked back 5 days or so:
Jul 25 01:44 - "You" sells "KING HAYBOL" 10k MP at 30 gold each (listings usually around 100 gold each, or higher), then also sells a couple thousand to other listers at 135 and 140 gold - very obviously doing so to only look less suspicious
Jul 21 20:23 - "You" sells "KING HAYBOL" 30k wood at 10 gold each (listings usually around 70 gold)
Jul 20 19:48 - "KING HAYBOL" sells "You" 7800 iron at 180 gold each (weird that when the buyer and seller swap, the price is much higher and at market value, not suspicious at all)
Not saying this is multi abuse - but it's very obvious that the intention here is for one kingdom to be getting the benefit of these exchanges and instead of sending aid they just do it through the market. Every time that "You" participated in the market Haybol was involved, which is quite odd. I only looked at these 2 kingdoms because of the other issues raised from multiple people in the past regarding castle passing and the smaller account being used as a TS machine. That combined with these market transactions (I'm sure there's many more that are equally suspicious, just don't have the time to go that far back but I might this weekend), and it makes things look a lot worse than if you were just looking at how much aid was sent between kingdoms.
Maybe I'm way off base here and am completely wrong about the 2 kingdoms mentioned, but my point is people are going to push the limits on any system that is in place. The question is do you completely change the landscape of sending aid like other people are discussing in posts above to catch a few shady characters? They are going to try and find ways to do is regardless of what is in place, and from the looks of the KHOF it hasn't really made a significant difference.