We know that a great deal of our critical national infrastructure depends on complex cyber-systems; but in the fast-changing world of the internet and computer systems, it's become impossible for slow-moving legislators to catch up to the shifting goalposts. Hackers and similar groups have had major impacts on society. But most of what's been visibly done so far has been limited to what you might call petty crime; theft, extortion, exposure of secret or sensitive information. But, as our systems increasingly depend on these complex networks, there is a disturbing question we can't answer. How much could a determined group of cyber-criminals disrupt society? Could they find a way to compromise highly sensitive weapons systems? Could they trigger a nuclear war? Coming in at number 8: Cyberwarfare.  I'm not an expert in this field, so if you have any opinions, thoughts, or facts I should be aware of - please, get in touch with the show @physicspod and we'll shoutout to you!