When ever a strange login attempt is made on your account Blizzard will ask you to confirm your account is safe via a toll-free call and may ask if you try to login on a different computer or via a new system.
Blizzard has put together a FAQ about the new Dial-in Authenticator on their website
Latest Geeky Gadgets Deals
Disclosure: Some of our articles include affiliate links. If you buy something through one of these links, Geeky Gadgets may earn an affiliate commission. Learn more.