I've always wondered if there is a server-side transaction log in MMO games like this.
RMT has 12 bots, each gaining 40k gil per hour, they trade the gil to 'account X', (or buy overpriced item from 'account X' in bazaar/MW)
Couldn't they just track the gil and ban 'account X' as well? This method would eradicate months (if not years) of RMT gil accumulation.
On top of that, they could ban entire IP adresses from known RMT.