It happens, but it's not very common, and decent folks step in and do something about it rather than run away. Of course it's easier to do something about it when you haven't been disarmed and made defenseless by your own government.
I was lucky on the New York Subway when a gang of youth tried to mug me, there were two plain clothes police there, but before they intervened the other passengers averted there eyes.
"It happens, but it's not very common, and decent folks step in and do something about it rather than run away."
BS