The perception being around blacks is an invitation to ask to be raped, assaulted or murdered is probably unfair when you're looking at it in terms of individuals. But when you know blacks as a group are more prone to criminal behavior that changes people's outlook to one of risk avoidance. This is not just restricted to whites. Black cabbies won't drive you into certain neighborhoods that they know are dangerous. You may as the DZGD believers do, this is just sheer racism. But I think there's something more to that with the ability of human beings to appreciate group differences. Quite frankly speaking, I wouldn't want to live in a Muslim neighborhood either as a non-Muslim.
"Show me just what Mohammed brought that was new, and there you will find things only evil and inhuman, such as his command to spread by the sword the faith he preached." -Manuel II Paleologus