[tomseldon]

They give permission to modify their computer/device, but obviously there's an implicit trust that it isn't going to do something horrifically bad.

Trusting a builder to come in to your home and change things- you'd be pretty angry if they took down a supporting wall to put up a new light fitting (and you'd probably have some legal comeback).

[sneak]

Yes, in civil court. What part of it should be illegal?