Users
While I would pass you litmus test, it's more because I am a bit paranoid about introducing unknown s**t onto my computers.
As for users, it's not their fault if they expect their computer to work properly. I mean here in the real world, how often do you hear about people dying because they opened their newspaper, and there was an article that made their brain explode? And from the description here, they receieve the email from someone they know.
I blame it all on the OS writers. There seem to be 2 options for files:
Option 1. Don't open it, look at it, or even allow your pointer to move over it. (This fails because of autorun etc.)
Option 2. Run, look at etc. the file. This gives it almost complete unfettered access to everything. It can use any resource it wants, and can persist forever without any way of getting rid of it or working out what it has been up to.
In my book, execution is not an automatic right. It should be possible to say what resources any program/file can have (e.g. why should a webpage turn on my webcam?). I think everything should be run in it's own sandbox. Users shouldn't have to worry about this kind of thing.