As an update to the security breach
last week, players on North American realms will now be prompted to change their security question and answer when logging in to their Battle.net accounts. The security breach included no financial information; however, answers to personal security questions were compromised, as well as some information related to Mobile Authenticators.
In addition to the security question update, players may now also update their Mobile Authenticators as well. Please note, this is only in regards to North American accounts; players in Europe need to do neither of these things. And remember, if you are a North American player and have not changed the password on your account, doing so is an excellent idea.
As a precaution following our recent security update, players on North American servers please take a moment to visit Battle.net account management, where you will be prompted to change your security question as well as update your Mobile Authenticator. There you'll also find helpful tips and an FAQ, as well as instructions on how to add additional layers of security to your account, including the Battle.net Authenticator or the Mobile Authenticator for those that aren't already using one.