Ask HN: Login Name as Alternative to Username

Noticed MSN account was getting multiple sign in attempts a day from IP addresses in Russia or Africa. Realizing it had become a target, I could assign phone number as primary login. And remove login via email address.

Thinking about making this a generic security practice. For all accounts with public facing usernames.

Is this something talked about in security circles? I have to go through workarounds to make this possible for certain accounts. So this is not easy.