Since the days when people began storing things in secret locations, there have been others waiting to pick the lock, steal the combination, and steal whatever was being hidden. In the age of the internet, keeping your personal data hidden becomes more difficult as the days go on, and developers have been on the assault against account thieves.
Cryptic is beefing up their security with Account Guard. When the user attempts to log in from an unidentified computer, the system will send a key to the email address associated with the account. The key must be entered, otherwise the user will be unable to log in. If there is a failed attempt at logging in, the user will be notified by email.
The system can be opted out of if the user prefers not to enroll.
(Source: FAQ)