There is an entire class of people that live in such conditions, and there is an entire class of "businessmen" that prey on such people.  When I was growing up, there were lots of headlines about "slumlords" that were taking advantage of the poor.  According to the Merriam-Webster dictionary, a "slumlord" is "a landlord who receives unusually large profits from substandard, poorly maintained properties".  Today, we have a different sort of a problem.  "Vanlords" are parking vans, RVs and trailers along the streets of the worst parts of our major cities, and they are renting them out to people that cannot afford regular homes.  Sadly, we live at a time when lots and lots of people cannot afford regular homes because homelessness is absolutely exploding all over the nation.  In some areas there have been efforts to crack down on the "vanlords", but when things get too hot in one area they just move somewhere else.  As long as there are vast hordes of homeless Americans that are deeply suffering, there will be "vanlords" that are eager to take advantage of them.

Matt Feely just authored a very interesting piece about this phenomenon.  He says that things are particularly bad in the poorest sections of Oakland…

The most familiar and ominous form of homelessness in Oakland, however, has become the vehicle encampment. A few small clusters of vehicles have gathered in my North Oakland neighbourhood, lines of dirty campers and battered cars seeking shade under an elevated freeway, but poor East Oakland has it the worst. There, such encampments have taken over long stretches of busy street, visiting already-distressed neighbourhoods with huge living sculptures of ugliness and disorder — cars filled with clothes and junk; hulking RVs parked for months at a time, drug and sex deals conducted streetside; trash gathering around and between the vehicles, and lots of new crime. Recently, the city had to replace traffic lights at an East Oakland intersection with stop signs, because people, presumably from the vehicle encampment close by, were constantly stealing the cables to sell the copper wire inside.