well its not quite like that. Basically there is the ghetto side, but what ends up happening is that these guys from the ghetto (generalizing here) will buy and resell. Thus on launch day, they were fighting with eachother to get these systems, because a Ps3 can sell for over 5 times its cost. Most of the people in these lines were different minority groups there to make profit.
This is not all the locations, most were fine enough. But the Electronic stores near the rough areas were basically battle grounds.
Lets put it this way, i talked to one hispanic guy the other day. He was able to buy 10 ps3's on launch day, he made about $25,000. From reselling them on ebay. A lot of other ghettolicious people had the same idea. Therefor, it will cause problems in certain neighborhoods.