There's a very nice scenario descibed in Lars Wilderängs book "Stjärnklart". Unfortunately it's not translated to english yet. I added some of my own parts to the story.

SPOILER ALERT

Suddenly, in Sweden and elsewhere around the globe, electronic equipment starts to fail, the car repair shops experience a large influx of customers, cell phones go black and payment systems stop working. Modern day society which is largely optimized for high efficiency rather than robustness, rapidly falls apart as payment system, transport vehicles and other infrastructure become unusuable.

Eventually, scientists discover that the dead electronic equpiment is covered in gray dust, which turns out to be caused by nano bots operating on and through electronic conductors, multiplying by consuming the electronics itself. Maybe it's a renegade government project? Maybe it's just an evil scientist who likes to watch the world burn.

In a few weeks, faced with starvation, dehydration and lack of sanitation, civilised people realise that to survive, it's every man for himself, or at best, every town for itself. In the power vacuum created by striking police officers who have no reason to do their job, local warlords are born.

Since most food production today is completely dependent on both electricity and oil, which must be transported, the wast majority of people starve to death within a few months. The nano bots eventually face the same faith as they run out of electronics to consume, but the world they leave behind is almost completely void of any working modern day technology, and all that remains of humanity is a few million savages.

There's a very nice scenario descibed in Lars Wilderängs book "Stjärnklart". Unfortunately it's not translated to english yet. I added some of my own parts to the story.

SPOILER ALERT

Suddenly, in Sweden and elsewhere around the globe, electronic equipment starts to fail, the car repair shops experience a large influx of customers, cell phones go black and payment systems stop working. Modern day society which is largely optimized for high efficiency rather than robustness, rapidly falls apart as payment system, transport vehicles and other infrastructure become unusuable.

Eventually, scientists discover that the dead electronic equpiment is covered in gray dust, which turns out to be caused by nano bots operating on and through electronic conductors, multiplying by consuming the electronics itself. Maybe it's a renegade government project? Maybe it's just an evil scientist who likes to watch the world burn.

In a few weeks, faced with starvation, dehydration and lack of sanitation, civilised people realise that to survive, it's every man for himself, or at best, every town for itself. In the power vacuum created by striking police officers who have no reason to do their job, local warlords are born.

Since most food production today is completely dependent on both electricity and oil, which must be transported, the wast majority of people starve to death within a few months. The nano bots eventually face the same fate as they run out of electronics to consume, but the world they leave behind is almost completely void of any working modern day technology, and all that remains of humanity is a few million savages.