but it has its problems.
One is someone outside of the car can control the car by presenting himself as a possible pedestrian about to be hit by the car. This can then cause the car to stop so now the driver and his passengers can be robbed or the car stolen. (However, I believe the market for hot self-driving cars will be very small.)
Once (if) self-driving cars become more common, have advanced beyond the lab/limited field testing stage to actually being sold, it will be interesting to see if robberies and and possibly accompanied by car hi-jackings become more common with these vehicles.
The self-driving car sends a signal of sorts the occupants are not all that aware of their surroundings have chosen to not be aware of their surroundings. An article in one of the UK papers detailed how one's walk sends a signal to the criminal element of one's vulnerabilty. Self driving cars will send the same signal.