I agree. I understand the motivation to not have un-banked people locked out of the economy (although I don't know how big a problem that is in San Francisco y

I agree. I understand the motivation to not have un-banked people locked out of the economy (although I don't know how big a problem that is in San Francisco yet - if it's only a couple experimental checkout-less stores it doesn't seem like a huge deal). But maybe a better eventual solution to that would be for everybody to have access to some basic banking services (and some sort of electronic payments). I think many countries provide it at post offices.