When was the last time you read about a mass bar fight

I don't read about them (bar fights aren't newsworthy), but they're hardly unheard-of hereabouts.

or some impromptu vigilante action against street criminals in your corner of the world

I believe the relevant violence is by street-criminals, and they're all over the place.

the organized crime that's rampant among the underclass

"Underclass"? And how, pray tell, does one recognize such a person? Hat color?