Some people cannot afford a passport. If they are on SSI, then obviously they don't have enough funds to pay for a passport after paying for the bills, food, et cetera. So it is a catch-22--
you want to save money by living in a cheap country over the border BUT you gotta save up a bit to BUY a passport and it is against SSI's policy to save up without informing them...
and if you tell them "hey I need a passport" then they are all OVER YOU.
Catch-22.
