This is what happens when you try to remove the root of an Ubuntu machine. At the end, when I tried to open one more term window, the computer crashed.
A few years ago, I was giving an intro to Linux course for freshmen and as an illustration that they couldn't sudo into our uni's servers, I jokingly asked them to try to remove the root (it was a very hands-on course). Of course they couldn't. But then, the question remained... What happens when you actually execute "sudo rm -rvf --no-preserve-root /"?