In my area of London a cohort of women sell the big issue, always outside waitrose stores. They rotate around different stores in the area on different days, so seller A will be at one store on Monday then move another on Tuesday to be replaced by B etc.
Several times I have seen these women using very recent iphones (and trying to be discrete about it) and I saw one last week being picked up by a man in a very new luxury car.
I think the big issue should be more aware of situations like this and try and prevent it? Aside from anything else I'm sure these women may be being exploited themselves.