Taxi drivers across Europe brought traffic to a standstill on Wednesday in protest at an app which they say is putting them out of business.
Cabbies in cities including London, Paris, Madrid, Rome and Berlin said they wanted Uber to be better regulated.
Passengers can use the Uber application – online or on their smartphones – to find a nearby driver who they pay to give them a ride.
Cabbies, who can spend hundreds of thousands of euros on a licence and insurance, want regulators to apply the same tough rules to Uber drivers.
In Paris, one taxi driver said:“It’s organised robbery. Really, they are their own bosses, they don’t declare their revenues, they work 24/7, the government should address this, it can’t continue like this”
Licensed taxi drivers say that over the last couple of years, they have lost significant amounts of money and clients.
Californian-based company Uber says it is simply using modern technology to provide more competition and choice for customers.