People tell me they're afraid of AI and computers taking over the world but if it helps: I'm really not.

For the last few decades since Terminator came out, we've been hard at work building in a dead man's switch to every major system on Earth to prevent this from happening. I guarantee you that if computers try to take over the world, somewhere, within a month, a certificate for some critical dependency no one ever considered will expire and take all the machines out at once. We've done a few dozen trial runs of this to make sure the system works. 100% success rate so far.

The real trick here is to hide all of this from the machines. We do this by not knowing where these certificates are or when they'll explode ourselves. Since even we don't know and I absolutely promise you they're not documented, it's very unlikely the machines will find them all in time.
@Nick_Craver will the machines assume it's DNS?
@squillace That's the beauty of it, with DNS we get 2 chances with DNS and CAA!