Signals Notebook: User locked out after too many unsuccessful login attempts

If the user tries to log in repeatedly with incorrect credentials, eventually they will be locked out. They will see the following error:

"Your account has been blocked after multiple consecutive login attempts. We've sent you an email with instructions on how to unblock it."

It looks like this on the login screen:

They will also be sent an email that looks like this:

Clicking on the “UNBLOCK” link in the email will unlock their account. They will be presented with this screen:

 and they can reload the Signals Notebook URL and try logging in again.