If you thought that nuclear war, climate change or AI represented the biggest threats to the world - think again. That's the message of this gripping documentary that tells the story of the most daring and audacious bank heist in history - perpetrated not by a bunch of masked figures with automatic weapons and getaway vans, but by a small group of sophisticated hackers and other hired fixers, and started by a simple malware attachment in an email. They got clean away with less than 1/10th of the billion intended. But that's still a vast amount of money for a single job, and more than enough to fund future and increasingly sophisticated crimes.

And if that's what a small group of criminal hackers can do, think what a nation state can achieve if it wants to bring down the entire financial, transportation, communication, energy, industrial, commercial and other essential utility infrastructures of its enemies - essentially to make them grind completely to a halt, putting millions or billions of people at risk. Then look at the world as it is now, with the increasing east-west polarisations of the major powers in the new Cold War. Every reason to be very afraid indeed.

Essential viewing.