I doubt you have the right to cut off the engine while the car is being driven. Also in the example cases you mentioned you have the right to do something with

I doubt you have the right to cut off the engine while the car is being driven. Also in the example cases you mentioned you have the right to do something with property that is legally yours. The problem comes in the fact that someone else's computer is not your property so no you should not be allowed to install rootkits and take control of their computer. The best example of what your talking about is DRM which is already legal.