Here is the deal. Not all are bad people.
I worked with a guy that spent time in Big Mac for rear ending a highway trooper on new years eve.
When he got out, and came back to work, he wore his prison jacket, pants, etc. I see people on the highway with the same clothing, so I figure they got their discharge, and are on the road to somewhere.
Dangerous? Who knows.
I've picked up two in my life. One was a man and women in NJ during a terrible hail storm, and an other around PC that was a native American walking down the road at -10F. Both times it was a non-event, but I had major firepower in my hand on the off side.
Goggle what your interested in, and its kind of scary what you'll find.