Vengeance is not the point; change is. But the trouble is that in most people's minds the thought of victory and the thought of punishing the enemy coincide.
All prisons that have existed in our society to date put people away as no human being should ever be put away.
After the revolution, it might very well remain necessary to place people where they could not do harm to others. But the one under restraint should be cut off from the rest of society as little as possible.
People who attack others need rationalizations for doing so. We undermine those rationalizations.
After the revolution, surely the only good reason for institutions that could still be called prisons - because they take people and place them under restraint - is this reason: wanting to keep people from harming others.