[kamjam]

I recently went abroad and due to a couple of issues I had to reinstall the OS on my phone (I did this during the flight). Since my Facebook app was not authorized on this phone I had to go through "extended verification" because Facebook had identified I was not logging in from my usual location. Verification involved looking at 10 or so photo's and verifying friends which they had identified. There was also the option of FB emailing a verification (I seem to recall).

The point is, they already have the means of verifying accounts without requiring mail in of government ID. If this was for a "business page" then uploading company documents etc to verify ownership, particularly in cases of dispute, makes sense but for personal accounts there really is no benefit (except to Facebook for some bizarre reason)