In the 1999 BBC "mockumentary" series People Like Us, there's a moment where an estate agent turns to her computer to assist her with a property search. It beeps, and she looks at the camera, saying: "It just says 'ERROR'." The ensuing awkward pause perfectly encapsulates our helplessness in the face of computer malfunction – and this is something that customers and employees of NatWest are horribly familiar with after the problems of the past week; locked in a tense stand-off, both parties blameless, but rendered impotent by systems beyond their control.

This particular fault is so enigmatic and mysterious that it's been referred to by spokesmen only as a "technical glitch". The money seems to be on an inadequately tested software upgrade that's backfired horribly – but it's a glitch that's had profound consequences. Banking, more than many industries, has been transformed by computer networking; once a relatively lo-tech, personal industry, it now depends entirely on the free flowing of digital information. We take the movement of such data streams for granted, but rarely consider the consequences of their stopping. Yes, we may read articles where intrepid journalists try to "live without the internet" for a week, but that represents little more than a lifestyle change. If computers stop talking to each other altogether, society falters.

We're living amid an Internet of Things, where the number of devices hooked up to the internet is greater than the number of people using it – and it's growing exponentially. Within years there'll be trillions of sensors embedded within our environment, exchanging information and developing intelligence to help to manage all kinds of resources – animal, vegetable, mineral – better than humans ever could. But while the internet as a whole is pretty resilient to attack, individual systems are less so, and we're going to become increasingly at the mercy of lines of code that we don't understand.

As the fallout from the NatWest meltdown lumbers on and the failed systems return to something resembling normality, I think of the IT departments who put things right as the fifth emergency service, with fire hoses and defibrillators replaced by laptops and passwords. In the years to come, we'll frequently look to them to rush gallantly to our rescue, deploying their skills to save us all from disaster. And if that's not an image to change the minds of kids who think a career in IT is boring, I don't know what is.