I noticed that San Francisco has a lot of homeless people sleeping in the sidewalks and that there is a lot of litter also. Now, how to get those people to help pick up the litter? How about this: no more money for them until they obtain and keep an affordable photo-ID card that is issued by the SF County (if they have no State-issued DL license or ID card). No money, not one penny or vouchers or anything without that card. We can make good little Boy Scouts and Girl Scouts out of them if we insist on the ID card first. Then the people who give out the vouchers and other benefits must record the card, maybe via a computer and web sites to the city records. We can record them getting their benefits into the City databases and be strict and rigorous about it, even if we have to pay the City workers to administer it more money.
After they get used to carrying their papers (those ID cards), then we can gently effect social change. We will hire leaders from amongst the homeless themselves to bully their fellow homeless people into better behavior. This change can be effected slowly, over several years so that nobody objects. Eventually, these homeless people can be given a sense of purpose and accomplishment and then we can lead them by the hand into better citizenship and it will be a very good thing. But we must be maniacal about that photo-ID card and keeping some records related to the photo-ID card.