As reported on Kotaku via Yonhap news, Maple Story - the hugely popular Korean MMO - has had it's Korean database compromised by hackers. The incident has been reported to the Korea Communications Commission by developers, Nexon.
The Korean server was attacked last Thursday. Player's user IDs, player names, passwords, and residential registration numbers were all compromised. Don't know what a residential registration number is? You're probably not playing a lot of Maple Story on the Korean servers so don't need to worry.
The details were encrypted but Nexon recommends that anyone who might have used the same password on other accounts change it immediately.
You're probably used to doing that by now. Sony , Codemasters , Bioware and, most recently, Steam have all had their databases attacked by hackers. These are sad times indeed; Uplink was fun. This isn't.