Users shouldn't expect a webpage or microsoft word to turn their computer into a helicopter.
A lot of complaining for a website you will have visited 5 seconds in your entire existence.
Your computer is fine.
Wait, can you turn your PC into an helicopter with a simple web page? Technology is amazing these days.
It's a minor step since you already can download a car.
Which you should not do of course :)
I wouldn't!
Yes, but it requires support to WebHelices which is on the experimentation phases. There is a shim using WebWings 5.0 but it only works on Chrome Canary, because foxes have legs instead.
A user with that expectation would make sure to turn off javascript. Which probably should have been the default in web browsers, but that particular ship sailed long ago.
Better close the browser tab before your computer lifts off!