Sure, they can "just" do that - if they know how or are interested enough in the machine to learn, which is kind of my point. If kids grow up with machines tha

Sure, they can "just" do that - if they know how or are interested enough in the machine to learn, which is kind of my point. If kids grow up with machines that restrict their behavior, they'll come to accept those restrictions as the norm. Some will be curious enough to learn to install a new OS and such, but they'll be the exception and not the rule.