well, here i beg to differ. i think there are some places they could not escape from... just don't give them any natural resources. like, napalm a little island, make sure there's a decent source of fresh drinking water, give them a pole or two for fishing and maybe a pack of matches and maybe even air drop them some food and clothes from time to time. if they want shelter, they can tunnel underground. that would be sweet. i think you have a point about them escaping, but what i'm saying is that it could be denied them. you can't make a raft without wood...