So... hackers intent on causing 100 million dead human beings have all the capability of simultaneously crashing all trains or all aeroplanes, but don't because they need them to travel...
... so instead they'll wait decades for autonomous cars to become mandatory (because they don't need cars to travel) and crash those?
What?
They account for 20% of the USA's electricity, and in 2017 were behind solar and wind in terms of the power produced. That aside, that's not a reason why hackers intent on causing 100 million dead human beings and have the capability to hack through any firewall and cause simultaneous meltdowns at nuclear power stations haven't done it yet, despite at least three decades to do so.
Simultaneous worldwide nuclear launches would guarantee a massive death toll, like the 100 million the hackers are intent on causing and have the capability to achieve by hacking through any firewall. And it's intensely easy to avoid where they would strike - just don't be in Europe, Russia, the USA, China, India, Pakistan, either Korea, the Middle East (especially Israel and Iran), or Japan. South Africa and Brazil would be good places to start.
I mean, you know that hackers just need a phone line and can do all of this from anywhere in the world, right?
So far, the reasons you've given for hackers intent on causing 100 million deaths and the capability to hack through any firewall to cause them not doing so with trains, aeroplanes, nuclear power stations or nuclear missiles amount to "*shrug* I unno". So why would they do it when autonomous cars are commonplace?
It rather sounds like you're just terrified of terrorists, or you've read three too many books about an electronic apocalypse. Why are the invincible hackers not wiping out banks, or Amazon, or crashing any other AI, or doing anything with all the internet-enabled devices we have to kill hundreds of millions of people right now if they can?
Ah, "I heard it happened before". Well that's concrete and completely watertight.
[Citation needed]
"Science" (technology) may be advancing quickly, but law isn't.
At present we've had level 2 autonomous cars (can steer and control pedals, but you need to keep your hands ready on the wheel) on the roads for around a decade. When they crash, we still don't know what to do about them, because the law hasn't caught up to them yet. In ten years!
A level 3 autonomous car (like level 2, but you don't need to keep your hands on the wheel) will be introduced next year. It's not legal to use its ability anywhere in the world yet (and its ability is to execute lane changes, braking and acceleration at speeds of up to 37mph, only on roads where there are two or more lanes and traffic is divided from oncoming traffic by a physical barrier).
Level 3 and Level 4 (fully autonomous within geographical confines) autonomous cars are in a testing phase, and have been for ten years, on private roads. Some, like the Navya shuttle bus, are allowed on public roads by special dispensation from local authorities. None are permitted free testing countrywide in any nation on Earth. There are no level 5 autonomous cars (fully autonomous, no driver or driving controls) beyond a couple of prototypes claimed by Ford.
Autonomous cars have been mooted as far back as Futurama, at the 1939 World's Fair. Probably further. Manufacturers have been working on them since the 1980s. It's 2018 and you can't use a hands-free system legally anywhere on Earth yet, because the law can't keep up with the technology - and it's had eighty years to get used to it, and more than thirty years to seriously get used to it - but it still can't work out what to do when a level 2 Tesla autopilot system has a prang.
We might be getting a production flying car before we get a production autonomous car, and flying cars are one of the longest running jokes about vaporware.
Nor is the market keeping up. Do you know what the first hybrid car was? It was the Porsche Mixte in 1900. It took nearly 90 years to get to a production-ready hybrid car, the Audi 100 Duo. After that it took a decade for an actual production hybrid, which was the Toyota Prius in 1997, or the Honda Insight in 1999 if you weren't Japanese. You can take that approximate timeline as a guide for autonomous cars if you like - after all, they've progressed at a similar pace - but we're looking at the market. It's now twenty years since the first production hybrid-electric vehicle, and how many do you think we're buying? Over here in the super-progressive, liberal UK, they make up five percent of the market now. Yes, five.
20 years since the HEV was introduced, they make up 5% of new car sales. They're on the rise, but only at the expense of diesel so far - petrol seems to be fairly static. If they continue rise at the same rate, it means they won't match petrol until 2025 and won't even represent the totality of the market by 2030, when a bunch of governments around the world want to ban standalone internal combustion (ICE) cars. And that's only new car sales. It's going to take another ten years after that to get the majority of the older ICE cars off the road.
That's 140 years from a functioning invention to ~100% representation of hybrid cars.
So far, autonomous cars are treading the same path. And, thanks to the unique nature of who's responsible for the driving and the ability of lawmakers to vacillate, they haven't even reached the stage where they can be tested on public roads freely, never mind actually sold to people. And then it's going to take decades for the market to accept them, and decades more until they can be mandated - if indeed they ever will be.
I think fifty years is optimistic for mass production and purchase of autonomous cars.
But don't tell me, you heard it happened before...