overall, i find this funny, this happened b4 and ppl dont learn, maybe banning everyone that bought stuff from this guy is too much since its lots of ppl, but i think taking 50% or more of everything they have (ms, spy lvls, army size, weapons etc) would be fair, even if they just bought 1 trill naq, they should have known better

if u really want to spend real $ in the game, there is an ingame market, u can buy things from there, and its oficial goods, thats the only place ppl should be using $ even if u pay more, at least you know your protected
@admin, from your post:
Forum wrote:he got those stats by a cheat. (tamper data or similar, stuffing a form value).
that cheat resulted in the auto-ban kicking in, accuont was banned.
i was asked later to look at the account, and verified the cheat, and autoban.
in short - a cheat stop tool in place worked. period
it seems your not exactly sure on how he cheated, i believe that should be the first priority, dont put your faith in the the cheat stop tool you have, go through every log u can find from this account, and check the date he got big amounts with the logs from the server, and try and do the same thing, theres probably a hole somewhere in your code, since he gets unbanned from time to time, and can do it again.
just ip banning doesnt work, thats been proven lots of times, its easy to pass that, you talked about your unix server, well, u can check all transactions the server had from the last couple of weeks, and see if its you that is accessing it

dont think that its impossible to access, since you cant do it yourself, nothing is impossible, thats been proven lots of times too
now what makes me sad, is the ppl that never cheated, always worked hard to get their accounts to the point they are right now, and get everything destroyed by ppl that used hot goods (even if they say they didnt knew it was hot goods) being someone that in the last 3 years, got destroyed a few times by cheaters and never got compensated, i urge you to start thinking more about the security issues the game have.
a suggestion i have is checking again the dev server connection with the production server, that was used a long time ago by some ppl that got huge amounts of naq like this time