Give them something to do that normally doesn't get done. I could think of them building trails and huts in national parks like the CCC did in the 30s. Or other

Give them something to do that normally doesn't get done. I could think of them building trails and huts in national parks like the CCC did in the 30s. Or other charitable things. Them working for cheap for profitable corporations is a massive market distortion which costs other non-imprisoned people their jobs.