Log in process reveals if an email address exists in the database

[henry.wright]

If an email address doesn't exist, this message is given when log in is attempted:

Unknown email address. Check again or try your username.

This, although debatable, isn't good practice.

[jorbin]

As mentioned on #53373, This is by design. There is a balance to be made between security and user-friendliness.

The decision to leave this alone has been made many many times as shown in the following tickets (if not others).
Related, duplicate: #3708, #4290, #5301, #12129, #22421, #31787, #45318

[henry.wright]

Thanks for pointing that out. I respectfully disagree but I do understand the push for user-friendliness