Sorry didn't have time to post thoughts when I made the thread. I think it could be scary to see what other things that could happen like this, such as implanting them into people's bodies, but I know that is probably still down the road.
Well that's a ridiculous leap. Your body is as 'personal property' as it gets. The only reason the GPS thing is an issue is because these cars are generally in public view, and trailing someone with a GPS is essentially the same as trailing someone manually, which you don't need a warrant to do.