Well, good question. If you go to a big city such as New York City, Los Angles, Chicago, or Miami, there are many dangerous places where you should not walk around at night. But, there are more safe places than dangerous places in the United States where living condition is excellent. One big problem that America faces today is gun control. You can purchase a gun easily with a cheap price.
Many people own guns, so sometimes it is pretty dangerous.
No, I've never been. I heard that the U.S. is very dangerous. So wherever you go, there is always a dangerous place. Oh, then I guess it's the same as Japan.