December 22, 2011 – 20 Million accounts affected
Chinese gaming site, 7K7K, was breached in December 2011 and 20 million user accounts were effected. user names, email and passwords were all compromised.
Some time during 2011 it is suspected that the Chinese gaming site 7K7K was the victim of a cyber attack in which approximately 20 million site user's information was stolen. The hack on 7K7K is thought to be part of a series of attacks that all occurred targeting Chinese IT portals, gaming sites, and social networking sites such as Renren and Kaixin.
The attack on 7K7K like many of the hacks against Chinese companies such as CSDN hasn’t been officially confirmed, but much of the account information stolen has appeared online that included user names and passwords. This fact leads experts to believe that the alleged attacks did actually occur.