Following an attack on Blizzardās Battle.net service last week, the company is today prompting all North American players to update their mobile authenticators, change their security questions and read up on a new FAQ/guide that gives hints on improving their accountās protection.
https://lastchance.cc/blizzard-network-breached-change-your-battle-net-passw-5933454%3C/a%3E%3C/p%3E
North American Battle.net Account Update [Blizzard]