Blizzard has reported that it has found instances of illegal and unauthorized access to its internal network.
Supposedly, email addresses were accessed, specifically for Battle.net users outside of China. However, no financial information has been compromised or, at the very least, Blizzard has found no evidence of such so far.
Aside from email addresses, answers to personal security questions and information relating to Mobile and Dial-In Authenticators were also accessed. In addition, cryptographically scrambled versions of Battle.net passwords were also taken. Though it would take a lot of effort to decipher these passwords individually, it is probably a good idea to change both your password and security question ASAP. Blizzard also recommends you change your password for any other services that share the same password of your Battle.net account. This applies for anyone in the following areas: North America, Latin America, Australia, New Zealand, and Southeast Asia.
Blizzard has stated that the investigation is still ongoing and they do not yet know who has accessed the data. However, they are working with law enforcement and security experts to get to the bottom of this right away.
By Angelo M. D'Argenio