French riot police push an overturned car as striking French taxi drivers demonstrate at the Porte Maillot to block the traffic on the Paris ring road during a national protest against car-sharing service Uber, in Paris, France, June 25, 2015. French taxi drivers stepped up protests against U.S. online cab service UberPOP on Thursday, blocking road access to airports and train stations in Paris and other cities. REUTERS/Charles Platiau 

A policeman secures the traffic as taxi drivers, who are on strike, burn tyres to block the access to Nice International airport during a national protest against car-sharing service Uber in Nice, France, June 25, 2015. French taxi drivers stepped up protests against U.S. online cab service UberPOP on Thursday, blocking road access to airports and train stations in Paris and other cities. REUTERS/Jean-Pierre Amet TPX IMAGES OF THE DAY

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French taxi drivers, who are on strike, demonstrate at Porte Maillot to block the traffic on the Paris ring road during a national protest against car-sharing service Uber, in Paris, France, June 25, 2015. French taxi drivers stepped up protests against U.S. online cab service UberPOP on Thursday, blocking road access to airports and train stations in Paris and other cities. REUTERS/Charles Platiau 

French taxi drivers, who are on strike, face with French riot police during a demonstration at Porte Maillot to block the traffic on the Paris ring road during a national protest against car-sharing service Uber, in Paris, France, June 25, 2015. French taxi drivers stepped up protests against U.S. online cab service UberPOP on Thursday, blocking road access to airports and train stations in Paris and other cities. REUTERS/Charles Platiau 

French riot police secure the Porte Maillot during a demonstration by French taxi drivers, who are on strike, to block the traffic on the Paris ring road during a national protest against car-sharing service Uber, in Paris, France, June 25, 2015. French taxi drivers stepped up protests against U.S. online cab service UberPOP on Thursday, blocking road access to airports and train stations in Paris and other cities. The slogan reads " Death to Uber". REUTERS/Charles Platiau 

French taxi drivers, who are on strike, block the traffic on the Paris ring road during a national protest against car-sharing service Uber, in Paris, France, June 25, 2015. French taxi drivers stepped up protests against U.S. online cab service UberPOP on Thursday, blocking road access to airports and train stations in Paris and other cities. REUTERS/Charles Platiau 

Flight crew and passengers drag their suitcases as they make their way towards Orly airport as striking taxi drivers block access roads south of Paris, France, during a national protest against car-sharing service Uber June 25, 2015. French taxi drivers stepped up protests against U.S. online cab service UberPOP on Thursday, blocking road access to airports and train stations in Paris and other cities. REUTERS/Christian Hartmann TPX IMAGES OF THE DAY 

Taxi drivers on strike burn tyres during a national protest against car-sharing service Uber in Marseille, France, June 25, 2015.
French taxi drivers stepped up protests against U.S. online cab service UberPOP on Thursday, blocking road access to airports and train stations in Paris and other cities. REUTERS/Jean-Paul Pelissier 

French riot police stand next to an overturned car as striking French taxi drivers demonstrate at the Porte Maillot to block the traffic on the Paris ring road during a national protest against car-sharing service Uber, in Paris, France, June 25, 2015. French taxi drivers stepped up protests against U.S. online cab service UberPOP on Thursday, blocking road access to airports and train stations in Paris and other cities. REUTERS/Charles Platiau 

Passengers drag their suitcases as they make their way towards Orly airport as striking taxi drivers block access roads south of Paris, France, during a national protest against car-sharing service Uber June 25, 2015. French taxi drivers stepped up protests against U.S. online cab service UberPOP on Thursday, blocking road access to airports and train stations in Paris and other cities. REUTERS/Christian Hartmann 

Policemen stand on a road as taxi drivers on strike block the traffic during a national protest against car-sharing service Uber in Marseille, France, June 25, 2015. French taxi drivers stepped up protests against U.S. online cab service UberPOP on Thursday, blocking road access to airports and train stations in Paris and other cities. REUTERS/Jean-Paul Pelissier 

French taxi drivers, who are on strike, block the traffic on the Paris ring road during a national protest against car-sharing service Uber, in Paris, France, June 25, 2015. French taxi drivers stepped up protests against U.S. online cab service UberPOP on Thursday, blocking road access to airports and train stations in Paris and other cities. The placards read "Uber go home". REUTERS/Charles Platiau 

An overturned car is pictured as French taxi drivers, who are on strike, demonstrate at Porte Maillot to block the traffic on the Paris ring road during a national protest against car-sharing service Uber, in Paris, France, June 25, 2015. French taxi drivers stepped up protests against U.S. online cab service UberPOP on Thursday, blocking road access to airports and train stations in Paris and other cities. REUTERS/Charles Platiau 

Passengers drag their suitcases past the taxi area in front of the Lyon Part Dieu train station as striking taxi drivers block access roads in Lyon, France, during a national protest against car-sharing service Uber June 25, 2015. French taxi drivers stepped up protests against U.S. online cab service UberPOP on Thursday, blocking road access to airports and train stations in Paris and other cities. REUTERS/Emmanuel Foudrot 

French riot police stand next to an overturned car as striking French taxi drivers demonstrate at the Porte Maillot to block the traffic on the Paris ring road during a national protest against car-sharing service Uber, in Paris, France, June 25, 2015. French taxi drivers stepped up protests against U.S. online cab service UberPOP on Thursday, blocking road access to airports and train stations in Paris and other cities. REUTERS/Charles Platiau TPX IMAGES OF THE DAY 

Taxi drivers, who are on strike, block the access of Nice International airport during a national protest against car-sharing service Uber in Nice, France, June 25, 2015. French taxi drivers stepped up protests against U.S. online cab service UberPOP on Thursday, blocking road access to airports and train stations in Paris and other cities. The slogan reads "Striking taxi". REUTERS/Jean-Pierre Amet