Or, if they get out of jail/prison in a state that allows marijuana legally, Washington/Colorado, some or all parts of cali and some other states, they can grow cannabis and might be much more lucrative than bitcoin/litecoin mining. Maybe safer to mine as growing cannabis is "federally illegal".
Not true.
I live in Colorado and grow weed and
1. It's illegal to sell weed unless you are a dispensary or caregiver, so no it is not lucrative.
2. Weed takes a lot longer to grow than you might think, and uses just as much if not more electricity than mining.
It's an alternative job. They could. And you sell your grown cannabis to the dispensary while you are licensed to do so. And yes, it is lucrative, why you think people are licensed to grow and sell. I bet it beats the the hell out of working at a fast food joints that ask for criminal history. How long would it take to solo mine a bitcoin vs growing a plant? Plant does not take so long to grow as you think, only few months, then the turn around profit after examined under microscopes, is phenomenal. In the long run, growing at fullest legal capacity, it might be more lucrative than bitcoin/litecoin mining.