Beta users can now add two-factor authentication to their user accounts.
Two-factor authentication will be optional for those who wish add an extra layer of security to their existing username/password. We only recommend this feature to those who are experienced with using two-factor authentication apps such as Authy or Google Authenticator. Note that it is the user's responsibility to back up the secret key and back-up codes - given that we collect very little personal information, it is difficult for us to verify your identity should you lose access to your account.
To setup two-factor authentication, go to 'My Account' -> 'Settings' -> 'security' and follow the instructions there.