As a trade-off to prevent legitimate users from trying to login with non-existent credentials, I display "this login does not exist" message. So unless the cust

As a trade-off to prevent legitimate users from trying to login with non-existent credentials, I display "this login does not exist" message. So unless the customers attempt to enter numerous different logins anyway - they are safe. I am not worried about bots trying to validate various account lists and build "existing users" list of my service, because those enumerating attempts are quickly prevented.