Image ©Licensed to i-Images Picture Agency. 11/06/2014. London, United Kingdom. Drivers of London black cabs \'gridlock\' the area around Whitehall. Drivers of black cabs 'gridlock' the area around Trafalgar Square and government buildings on Whitehall in a protest against the Uber app-based service. Whitehall, London. Picture by Daniel Leal-Olivas / i-Images