As a security enhancement, we temporarily lock your account after failed login attempts.
The length of time you're locked out increases after each unsuccessful attempt. This essentially nullifies the possibility of a brute-force attack because the time between attempts becomes incredibly onerous after a trivial number of guesses (trivial by a machine's standard, that is).
If you're a legitimate user and cannot remember your password after a few tries, we recommend resetting your password. It won't unlock your account, but you will be able to access your account with certainty after the timer releases your account.
If you try to log in and find your account has a really substantial timer, you can contact customer support.