Blizzard has offered users a variety of security options which they can use to help take protection of their Battle.net accounts to the next level. While there are reports of Battle.net accounts with authenticators still getting hacked, these are definitely fewer compared to those without. That being said, if you are using Blizzard’s Dial-In Authenticator to protect your Battle.net account, Blizzard has announced in a post that they will be removing the authenticator from related Battle.net accounts come 15th August.
Fret not though as Blizzard has other forms of authenticators, such as the Battle.net Authenticator and the Battle.net Mobile Authenticator which is basically an app for smartphones. So if you are using the Dial-In Authenticator, Blizzard has a how-to page setup that teaches you how to remove it from your account at which point you will be able to attach a new authenticator to it.