What a deplorable, luddite attitude. The black taxis should be banned for some period of time for this behavior. "The Licensed Taxi Drivers Association complains that Uber's drivers are using a smartphone app to calculate fares despite it being illegal for private vehicles to be fitted with taximeters." So using this website in your car is illegal?! http://www.worldtaximeter.com/
You're either a minicab offering pre-booked journeys or you're a taxi with a meter. If Uber is claiming they're a pre-booked journey service rather than a taxi then yes, they shouldn't be using meters and that would be illegal. If you want to change the law then by all means write to your MP or whatever, but in the meantime the law as it is should be enforced, even against fashionable companies.
This attitude puzzles me greatly. Rule of law is a principle, not a dogmatic application of The Rules Über Alles. Crap laws should be ignored.