It wasn't a blackmail scenario specifically Jagex got punished either way because the fraud was enabled by their platform. I don't have the time to check but I believe this was mentioned by the one of the Gower brothers in the runescape documentary. My broader point is that even if they cracked down on fraud which was absolutely not the fault of Jagex because of the poor security options at the time from Credit Card companies, they still had the issue of people buying gold from RunescapeGoldSeller.com and chargebacks