It missed us by 9 days

Such a security issue as well for the computational world. That's why using Blockchain would be a bad idea. Turning off everything loses the ledger and then what? How do you recover trust from that? With a centralized model, at least there's someone that is tasked with recovery - it may not be the best, but it works. If something was tampered with, you can sue them. With a ledger how are you going to do that? The first people to boot up again from the outage can come back with a different state of the world and you'd have to simply accept that.