"Some data was illegally accessed, including a list of email addresses for global Battle.net users, outside of China. For players on North American servers (which generally includes players from North America, Latin America, Australia, New Zealand, and Southeast Asia) the answer to the personal security question, and information relating to Mobile and Dial-In Authenticators were also accessed. Based on what we currently know, this information alone is NOT enough for anyone to gain access to Battle.net accounts," he pointed out.
Cryptographically scrambled versions of Battle.net passwords for players on North American servers were also taken, so players are advised to change their password. Thew will also be prompted to to change their secret questions and answers, as well as to update the software for the Battle.net authentication if they use one.