Suppose you get into a group without knowing that there is a farmer in the group? Now you're subject to possible banning just for being in a group with a "criminal" even tho you had no idea they are breaking/have broken the rules? Innocent players would be hurt by this idea. The main thing is that as long as there is some level of demand, there will be farmers. You can cancel accounts and ban CC#'s all day every day. If there is a market, the "industry" will find a way back in. The only way to kill off plat spam is to kill off any demand. I only see two ways to kill demand, punish players who suddenly come into huge sums of plat (like in a matter of seconds they have 500k+ plat, not from AH) or make plat even more easily made (likely to totally ruin the game) for the average player (IE- a lvl appropriate quest nets a player 5-10k plat in one run). Then we become like AC where cash is totally worthless and items are the only currency.