When the phrase "technological exoskeleton" is normally considered, one typically thinks of an enhancement to the human body. However! If you are strapped into one, that doesn't HAVE to automatically mean these two things:
1. You can unstrap yourself.
2. You are in control of the exoskeleton.
Prisoner Work Force, in past times often seen in the form of a gang of guys chained together, can today be done differently. Lock the prisoners into exoskeletons* that are remotely controlled. There are nothing but electronic chains linking this gang together, as they march off, exactly synchronized, to get even more work done than before.
*Paid for via ordinary non-marching municipal bonds, of course.