Square Enix announced on their official website that they have banned over 5000 players due to illegal activities which violate the ToS, therefore break the balance of the game. “Real money trading (RMT) and other illicit activities upset the balance of the game and, as such, are prohibited under the Terms of Service.”
This wave of bans took place between February 25th and March 3rd. “Players who discover any confirmed cheats should, under no circumstances, exploit or disseminate such information. Instead, we ask that players file a report by using the in-game command [System Menu] -> [Support Desk] -> [Contact Us] -> [Report Cheating].”
The same goes for RMT, Square Enix states that any spotted RMT advertisements should be reported through in-game command. They also promise that they will continue to take action against RMT in-game and keep on continuing to ban players who decide to do so.