Edit: I would suggest getting them involved in positive activities that scratch that itch. Does their school have a robotics team? Can you buy them a kit for building a DIY FPV drone? Got any projects of your own they can help you with? Are there any local competitions you can get them in? (Math, drone racing etc.)
As others have mentioned, things are better when he is on the straight and narrow. If he doesn’t want to work for a company, he can work for himself and consult / sell his expertise for companies that are willing to pay top dollar for finding serious securirty issues in their products and services.
Finding a mentor (as has been mentioned) will go a long way. Someone that had been trouble for himself and others - but decided to go on the straight and narrow - and basically provide and educate with various choices and consequences (both good and bad).
My parents didn’t understand my obsession for computers at a young age and I also went down a fairly black hat learning route.
I suggest you inform him via the likes of DEFCON, support groups, local hacker spaces. It’s easy to go down a wrong path in this field.