London's black cabs are in a league of their own, so when Hailo, an app specifically designed for those vehicles, announced that it was becoming a fully-featured Uber rival, things got a little heated. In fact, disgruntled drivers have vandalized the company's headquarters and are now rapidly departing the service. The platform has been losing ground to its less-choosy rivals, and so decided to admit that if it couldn't beat Uber, it would probably have to join it. Unfortunately, the threatened cabbies are also planning a (hopefully non-violent) assault upon Uber next month in the hope of pressuring the government to hold the service to the same rules and standards that commercial taxis use.