I have found these ways for Facebook to require verification:

1. Created a fake account in one country and used it a few times, then many many months later I tried to login from another country and Facebook promptly required government-issued ID.

2. Created another fake account and changed the E-mail address after a few days and Facebook promptly required government-issued ID.

It makes me really happy that so many are deleting their Facebook account, or at least trying to use it less.