LOS ANGELES — The growth of ride-hailing companies such as Uber and Lyft so far has not been hindered by limits from government regulators and campaigns by taxi cab competitors. A bigger threat to the new industry’s impressive start could come from customers — if enough people stop using the services over fears that drivers aren’t safe. Not safe as in the drivers won’t get into an accident — safe as in they won’t attack passengers. Uber operates in more than 250 cities in …