[jerf]

At scale, anticipating the interactions your code is going to have with the rest of the world is very difficult. See, for instance, https://www.computerworld.com/article/2517969/google-s-pac-m... . It's hard enough for normal code, but April Fools tends to exercise some very undertested pathways in both code and organizations, and the results are often unamusing, and potentially serious.

Google and Microsoft and such are the behemoths of the computing industry, and the metaphor works fairly well this time; imagine a giant trying to figure out how to "prank" all the Lilliputians around them. It's gonna end up with squashed Lilliputians, no matter how careful you are.

Leave it to smaller entities.

(Although I do want to say I'm speaking about "pranks" here, like hacking Gmail, or changing the Google homepage too much. Putting up a fresh new website with something fun and cool, something that you have to choose to go to, is fine. But that's not really an "April Fool's prank" anymore, just some new fun and cool site.)