As commercial ridesharing becomes more popular, it's eating into the business of traditional cab companies. Licensed cabbies are being replaced by part-time, unlicensed drivers using their own cars to make extra money. Hundreds of taxi drivers protested last week at Los Angeles City Hall against Uber, Lyft and Sidecar, what they all “bandit cabs” that use apps to find passengers and don't have special licenses or insurance coverage. Yesterday, London cab drivers brought gridlock to the center of that city. Is mobile technology spawning a mobile black market or is ridesharing the wave of the future?