> I would much rather see a mailed postcard, as the last-resort fallback to a TOTP. Better to be locked out of your account for 4 days waiting for the mail, than to be locked out of it indefinitely while the criminal has full access.
The homeless can receive mail. General Delivery, mail addressed to them care-of some charity organization or shelter, any family or friend.
Mail forwarding is a thing for those who move, although TBH it would be prudent to use the "Do not forward" option on this, as mail forwarding itself is prone to fraudulent usage.
I guess if you've moved, you would need to mail them proof that you lived at the old address and that you live at the new address. I had to do that to claim unclaimed property with the state -- I had to send them some old bills or legal documents showing the old and new addresses.
What happens to the homeless or move?