Sung-won Shim reports for Reuters:
… The Korea Communications Commission (KCC) said in a statement Nexon reported to the commission late Friday afternoon that the company on Thursday discovered the leakage of personal data of its online game Maple Story‘s 13.2 million subscribers.
[…]
KCC said it, jointly with police and computer security experts, is investigating the hacking case. The leaked data included user IDs, names, resident registration numbers and passwords, it added.
A Nexon official said the leaked data neither covered no information on financial transactions and bank account numbers. And it did not affect overseas subscribers of the online game.
Read more on Reuters. Thankfully the registration ID numbers and passwords were encrypted or this could have been a lot worse.