How will people react? I think it's too early.
+ Jealous cap drivers, truck drivers, neighbors can easily put some chewing gum or paint on one or a few sensors. The system will be too brittle to cope with that, so all the time your/the sweet self-driving car doesn't even want to start.
+ Joyriding and pranks. Put your silly little brother or the dog who you've to babysit in the car. Bye bye!
+ Criminality. Just put your drugs on board or a corpse. Or do the companies that own these cars use them as remote cameras all the time?
+ Insurance. Just set up a situation perhaps with multiple cars where the self-driving car slams in your insured car. Use some doll etc.
+ Destruction. Do the same to cause the car falling into the river or crashing into something you dislike.
+ Vandalism. Graffiti etc. will be recognized much later than with a human driver.
+ Theft of sensors or other car parts can be orchestrated on a location the car first drives to.