What surprised me is the relatively high amount of U.S. Cities on this list. I didn't expect to see Buffalo, Milwaukee, or Seattle listed.
Interestingly, there's was a Best Rated Places in the U.S. book written in the 1980's or early 1990's that listed Seattle as amongst the best places to live. While Seattle has some dangerous neighbors and some that were ultra leftist, in my trips to Seattle, I never got the impression that this was one of the most dangerous cities in the world.
Also, back in 1988 and 1990 when I spent a considerable amount of time in Milwaukee, one thing that jumped out was Downtown Milwaukee was the cleanest city in the U.S. I ever visited. It was the antithesis of the pre-Rudy G. NY City, which had litter all over the streets and sidewalks.