A pedestrian, right, walks past a line of London taxi cabs parked along The Mall, leading away from Buckingham Palace, during a protest against Uber Technologies Inc.'s car sharing service in London, U.K., on Wednesday, June 11, 2014. Traffic snarled in parts of Madrid and Paris today, with a total of more than 30,000 taxi and limo drivers from London to Berlin blocking tourist centers and shopping districts. Photographer: Simon Dawson/Bloomberg via Getty Images