Trust in a system
The slogan “if your minicab's not booked it's just a stranger's car” makes sense on the surface of it.
Until you realise that, of course, any taxi car is probably a 'stranger's car'.
The thing that makes your booked car not a stranger's car is that it is part of a system, and one that is reasonably predictable.
Working for a taxi company has a higher barrier to entry than just buying a car and parking up outside a tube station right? The driver is probably CRB checked, has a clean drivers license, or at least has a record with the company that makes him traceable and unlikely to try and rape you and do a runner.
How do you know this? You probably don't unless you've ever worked for a cab company. But by piecing together your knowledge of the systems that a make up a taxi company - an employee register that needs a bank account, and a bank account that needs an address - you can take a rough guess.
What happens then, when we have no longer have any knowledge of the systems that go into delivering a product or service?
Systems are usually created for a reason, by many people over a period of time with significant investment. They are more trustworthy than chaos, which has no such collective authorship.
What happens when the systems that we think we know require little investment to change, or are completely personal, will we trust them then?