As black cab drivers scrawled the word "Scabs" onto the offices of the taxi app firm Hailo, there could scarcely have been a more apt image for the confrontation between the old industry and the emerging might of Silicon Valley.
Right now the battle between cab app firms such as Hailo, Kabbee and Uber, against London's iconic black cab and minicab firms shows every sign of escalating. Uber chief executive Travis Kalanick's speculation that the firm's fleet of cars could one day be self-driving is unlikely to reassure drivers, and many cabbies are scared that their livelihoods are being snatched.
Yet taxi apps do not hold all the cards, at least in London where black cabs enjoy some legal protection. Uber may soon be hauled into court over their app, which calculates fares by relaying the distance and time taken to a computer server. Cabbies have argued this is effectively a taximeter, which private hire vehicles are banned from using, but Transport for London (TfL) did not see it that way, and has invited the high court to adjudicate on the matter.
Firms like Hailo argue that if cabbies isolate themselves from the apps they will be wiped out. Writing in an open letter announcing the decision, Ron Zeghibe, chair of Hailo, said: "There is no point burying our heads in the sand - people want a choice and taxis need to be in the mix. A taxi-only app will get isolated and customers will take their money to services without any cabs on offer."
Within days the firm's London office had been stormed by those who disagreed. But others believe cabbies have worse to worry about than the big app companies. Speaking to CBR recently, Dave Walker, chief technical officer at Kabbee, said: "Potentially there are apps out there which are more destructive to black cab markets because they are breaking the law."