Google OAuth2ユーザーが「user1」、「user2」などのユーザー名を取得するのを防ぐには？

[pmusaraj (Penar Musaraj)]

I am pretty sure this is coming from this site setting

If unchecked, the username picker will default to userN, especially if the user doesn’t have a display name in their upstream account.

Security 1, convenience 0