Yeah, Roberta, I kinda wondered about that too, but it allegedly was a Detroit-area localism, and had no ethnic connotations. I grew up near Detroit and don't remember the term, tho we had other localisms there--I remember kids at Halloween going door to door and calling out "help the poor" instead of "trick or treat"--we went "begging" , not "trick or treating"--and it seems that call has died out around Detroit now too.
Here's a discussion of "sheeny man":
While visiting with my grandparents the other day, my grandfather mentioned an expression I had not heard in some time: "the sheeny man." Originally "sheeny" was an ethnic slur used to describe immigrant Jews, but in the Detroit area "the sheeny man" referred to anyone who patrolled the alleys looking for value in the trash of residents.
In other words, a "garbage picker," though these days such people are more likely to be referred to as urban foragers, curb shoppers, or recycling entrepreneurs.
In Detroit during the 1960s and 1970s, the sheeny man was just as likely to be black as white, and this was one of those expressions passed from generation to generation that lost its ethnic connotations. While being called a "sheeny man" was certainly less glamorous than being called a "rock star" or "MLB starting pitcher," in the blue-collar Detroit neighborhoods in which I grew up "sheeny man" was just a work-oriented moniker, nothing more.
I recently remarked on another blog that I have spent almost the entirety of my life (with the exception of vacations and a brief stint living in Dallas) in the middle of the American Rust Belt in cities like Toledo and Detroit. I do not know if urban foraging is as prevalent in wealthier cities, but it is clear that plenty of people in decaying Midwestern cities derive a significant portion of their incomes by sifting through the trash of others.
What I find especially interesting is the rapidity with which items I discard get snapped up by folks driving through the neighborhoods. At times I scarcely return to my house before a rumbling old pickup appears to take away an item I place at the street, hauling away material that I considered trash but which has value to another person.
Of course, I am not immune to the lure of someone else's unwanted materials, and over the years I have procured from the trash objects that still possessed value and utility. These ranged from bikes to lawnmowers to snowblowers, though my wife will argue that much of the "wealth" I brought home merely collected dust until a yard sale or an inevitable garage-cleaning.
So pick away, ye dumpster divers and refuse gleaners: our landfills are less full and our garages are less cluttered for your efforts.
Everybody in Cambridge seems to fit that description. Stuff left out for trash disappears quick--impoverished students furnish whole apartments that way--backyards have the patio furniture someone else threw away, and of course the homeless deposit bottle pickers who support themselves by 2am foraging.