After I was mugged, about a year ago, for a time I kept my distance from other people on the street, but especially from black men. I felt terrible about crossing the street, or even flat our running, whenever I saw a black man, and wonder how he felt. Not good, I assumed. But I felt confident that by avoiding black men, I dramatically decreased my chances of a repeat occurence.
Today, I found this article by Brent Staples which gives the story from the side of the black man (in Hyde Park, no less). He doesn't seem to blame us skittish folks -- but it certainly affects his life more than ours.