The Black Cabs in London have a long-standing monopoly on picking people up on the street and providing a metered journey. This is mandated by law. To become a black cab (not always black in colour) driver, it is necessary to take an advanced test called The Knowledge where you are expected to know every London street and landmark along with best routes based on random street closures. It takes about 3 years to study for The Knowledge and there is evidence[1] that they have increased brain size as a result of memorizing all that information.
The other option for people wanting a car journey is the "mini-cab" which can be booked to collect from any specific location but must offer a fare in advance of the journey. In order to transport people for money, mini-cab drivers are licensed and have a background check done.
Uber drivers in London must have the mini-cab license so this is a question around the black cab monopoly. As with any government-provided monopoly, the incumbents are keen to maintain the status quo while the newcomers are fighting for change. Any advances that Uber makes will benefit all mini-cab companies and most importantly, passengers.