I did a quick search. CHIPS seems to be a popular name for all kinds of things.
" I have read there are groups of people that ride the trains and they are very territorial. They survive by robbing stray travelers on the trains."
This is pretty much true of the whole world in some form or another. Sounds to me like the kid wants swashbuckling adventure and danger. No matter where he is or whether or not you're in control, that's probably not going to change.
I think maybe FaceKhan had the best advice. Try pointing him toward types of adventure that you find more acceptable. Ever look into mountain biking? I'm not kidding. Around here, it's a lifestyle for some people. I've seen pairs and larger groups of cyclists blockade highways, slowing traffic to their speed. And they don't back down when the Harley variety of cyclists join the frey. So far, no deaths reported but lots of interesting human interest pieces and creative politics over bike access funding and such.
And resist the urge to think the worst. I know it's a strong one. Did I mention I have a 19yo daughter? She has no interest in trains or the "King of the Road" culture that I know of. Instead, it's a boyfriend straight out of a Ricki Lake episode.
Not a damned thing I can do but keep the door open and try not to make things worse. The kid doesn't want my help, she only wants cards, pictures, letters, medical advice and recipes. So that's what she gets.
Bureaucracy defends the status quo long past the time when the quo has lost its status
--Laurence J. Peter