Sure to annoy IT people but those just need a line of text while the rest of the screen is free real estate for Micro$oft! Public BSODs tend to go viral too.
I remember back in the day before browsers had much in the way of protection, and ads could do basically whatever they wanted on your computer. I distinctly remember seeing ads back in the 2000s that would go fullscreen and emulate a BSOD, with a number to call a fake Microsoft Support.