"Please note that we have removed the Dial-in Authenticator from our Battle.net security options. If you’re currently using the Dial-in Authenticator, it will continue to work normally until August 15, 2012, at which point we’ll be removing it from any accounts that have it attached.
If you’re not already taking advantage of one of the Battle.net security measures listed below, we strongly encourage you to select the option most convenient to you:
We also offer Battle.net SMS Protect, which can be used alone or stacked with one of the options above for an even greater level of protection.
If you’re currently using the Dial-in Authenticator and want to add any of these security options before August 15, you’ll first need to remove the Dial-In Authenticator from your account by following the instructions listed here.
We’re fully committed to account security, but please keep in mind that it’s ultimately a team effort. While making use of the available security options can go a long way in helping to protect your characters and items, it’s also important to be aware of the other things you can do to help ensure your account is as secure as possible. Review our Account and Computer Securityarticle for more."