The San Francisco protest is one of several demonstrations in the U.S. against Uber’s recent cut in fares.
Meanwhile, taxis have taken a huge hit in the transportation battleground.
France's highly regulated taxi drivers say Uber has hit their business unfairly as it has expanded rapidly.
A spokesman described Uber as “like getting in a sea full of sharks” for female passengers
"This about an all out assault on our profession, our livelihoods," said Max Small, a driver of one of London's black taxis for 34 years