Mark Zuckerberg, a chap who takes his own plans for world domination very seriously, once described Twitter as the clown car that fell into a gold mine. Twitter always looked set to change the world; but until recently, it never had the infrastructure to scale up properly.

Well good news, shareholders of Google. Your money now backs a prototype self-driving vehicle. This really does look like a clown car. It also really will take over the world. Cars that do not require a steering-wheel, pedals, or, in fact, occupants could release billions of hours of productivity. They might even lead to the world’s greatest ever logistics company. But, either way, Google will require infrastructure, at scale.

That means money. Shareholders provide that to Google without having any say about its use. That will not be sustainable for very long at a car company.