Diablo 3 Account Security

Blizzard Entertainment cares much about the security of diablo 3 accounts that players register and use to play the games.
Actually, account security is one of the top priorities, because Battle.net accounts are expected to be a convenient and worry-free way to have access to all your Blizzard Entertainment games and also connect with your friends through the Battle.net; one of our most important goals is to keep your diablo 3 account safe and secure.
These pages are part of a larger effort to offer you the knowledge and tools that are necessary to report and identify threats to your account’s safety, to spotlight ways where we work to fulfill our security commitment, and to act as a helpful resource in case that someone manages to steal account information from you.
Source: battle.net