You no longer need to see a vehicle to hail it. Your phone will see it for you. It will see round corners; it will see in the dark. You no longer need to hail a taxi by sticking your arm out or shouting; you just press a button and within minutes – seconds – the car will be at your side. The car can be parked up at a petrol station, or down a side street, or just dawdling in traffic, and – ping – it will be there. In other words the app is allowing private hire vehicles to behave like black taxis: to be hailed, to ply for hire in the streets, to do exactly what the law says they are not supposed to do. You have the instant (or virtually instant) accessibility of the black cab, with none of the extra costs entailed by the vehicle regulations or the Knowledge, and the growth of the business is huge.