Humans are terrible. When the computers take over.... I won't be happy about it, but I'll kinda understand.

Just shout "self-destruct" all the time and we'll be fine.

Alexa has 4-5 joke responses to self destruct. E.g. "I'll start the countdown but only on the understanding you'll dramatically cancel it at the last second", and "3-2-1 Boom. Hmm that didn't quite work did it?" or something like that, and a few others.

Like the countdown at the end of Monsters vs. Aliens:

https://www.youtube.com/watch?v=FJ5DA22tBOY#t=4m27s

“8… 7… 6… 5… 4… 3… 2… 1…

…

Hmm, nothing happened, maybe my count w… [ＢＯＯＭ]”

Selling a product that had a voice command UI we found that people will go out of their way to mess with it. Sometimes for fun, sometimes to unload their frustration. There is something strange about a voice UI and I think it is the expectation that the intelligence should be about the same level as human intelligence. If it is not there, and it is making the user look silly by making them repeat something obvious multiple times, they will quickly start hating the product as a whole. It's almost better not have a voice UI unless it is pretty darn good.

Yup, Mac OS 7.5 had speech commands, my colleague named his machine "Oi!" and I would routinely shout "Oi! Shut down!" as I left the office. Never got old.

Of course, and as was widely known (and mentioned when this subject came up) at the time, FORMAT C: would not have actually worked (on systems where C: was the boot volume) because OS/2 locked volumes that were in active use as filesystems, preventing them from being reformatted.