Taxi protests against Silicon Valley ride-app Uber threaten European gridlock

LONDON/PARIS (Reuters) - Commuters faced a day of traffic chaos in London, Berlin, Paris and Madrid on Wednesday as taxi drivers mounted one of the biggest protests against Uber, a U.S. car service which allows people to summon rides at the touch of a button.

Paris commuters faced gridlock getting into the city on Wednesday morning when taxis slowed traffic on major arteries into the centre. In London, up to 12,000 taxi drivers plan to tie up the streets around Trafalgar Square, just a stone's throw from Prime Minister David Cameron's official residence, from 2 p.m. (1300 GMT).