On a June evening in 2010, six Silicon Valley start-ups gathered at a waterfront venue in northern San Francisco to pitch to angel investors at an event that, at the time, seemed unremarkable.

But among the start-ups hoping to receive their first outside cheques from one of the 20-odd investors present was ride-hailing app Uber, then known as Ubercab.

Over burgers and beers, Travis Kalanick, at the time an adviser to the company, took the stand for five minutes to present his vision: a world where smartphone users could summon taxis at the tap of a button, thanks to geolocation