Google Street View cars have many ways of finding themselves in our world and knowing what is around them (which msftguy have kindly specified) but I guess GPS navigation is its primary instrument and without it it will be unable to drive anywhere. Device like this - http://www.jammer-store.com/gj6-all-civil-gps-signal-jammer-... - or maybe other one can easily block its GPS signal and stop it in case of emergency.