You raise two very valid concerns. That Hitler might hurt others if you allow him to interact with them, and that Hitler might find a way to escape the box.
Even if Hitler was willing to reflect on his actions and change, his presence in the network (B) would likely make other people unhappy.
So while I think (A) is ethically mandatory if you can contain him, (B) comes with a lot of complex problems that might not be solvable.
You raise two very valid concerns. That Hitler might hurt others if you allow him to interact with them, and that Hitler might find a way to escape the box.
Even if Hitler was willing to reflect on his actions and change, his presence in the network (B) would likely make other people unhappy.
So while I think (A) is ethically mandatory if you can contain him, (B) comes with a lot of complex problems that might not be solvable.