After finding the scoop from my co-workers, it is still as I thought (and has been for at least 25 years). Even though most of the older folks I talk to say it is a southern term, within the context of inner city life (one that has a very specific gang orientation), "folks" are the members or affiliates of the south side of Chicago, whereas "peoples" are the members or affiliates of the west side of Chicago. I thought for a while that it may be "race" specific (and it may have been back when I first heard the terms) but it is now very (apparently worth dying for) turf specific.