Some 500 taxis jammed streets in Warsaw as they rode in a mock funeral procession today during a protest against unlicensed passenger carriers, dpa quoted local media as reporting. One taxi carried a coffin saying, "the last licensed taxi driver," while hundreds of others caused traffic jams by driving in groups on a route passing the chancellery of Prime Minister Donald Tusk The drivers claimed the unlicensed carriers created unfair competition and drove down profits.