I had friend from Colombia, where every once in a while members of his family would be kidnapped and ransomed by guerillas. Kinda changed my opinion of the local hoods.
I lived in arguably the worst place in Boston, the Bromley-Heath housing projects, a place where suburbanites wake up in cold sweats from nightmares about, and had nothing but positive experiences really. Violence was generally just gang on gang, and the local community was very self-policing and everybody generally looked out for each other. Example: I woke up one morning to the sound of my neighbors (who I had never met) literally fighting off a tow truck operator from towing my car, saying "you're not getting any cars from this neighborhood you vultures". LOVE IT.
I an odd juxtaposition, one week after moving into my current upper-middle class Irish and italian "good neighborhood", my car was broken into and vandalized likely because of my pro-atheism bumper-sticker (which was ripped off and torn). Similarly, my neighbours constantly have somewhat violent fights and the paddy waggon is perpetually parked near the local pubs due to constant drunken brawling. Sure, self-selection bias on my part, but... weird huh?