The question might sounds sarcastic,but it's not meant to be: so why haven't any of those instances happen to Uber's user? Does it mean that the regulation already applies to Uber (to a certain extend). Or is there any other reason?
http://www.sfgate.com/bayarea/article/Victim-of-alleged-Uber...
edit: yes it happens in taxis too, but in that case it's pretty clear that the taxi company has liability. not so clear if it happens in an uber. see: http://www.forbes.com/sites/ellenhuet/2014/09/30/uber-driver...
The way I see it, there is no guarantee of safety in either situation. You never know if your driver is a criminal or crazy. But services like Uber seem considerably more safe: There is extreme record keeping, user ratings, and no direct money changing hands.