Allow me introduce you to Roko's Basilisk. Presumably so called because whoever came up with the idea must have been stoned at the time.
The short of it is that, when the Technological Singularity comes around, Skynet or whatever you want to call it will judge us for our sins, and punish those worthy of being punished. In particular, people who didn't help it along.
Hmm. What does this remind me of... Oh yeah...
Edit: BTW what is it with humans and the concept of vengeance? That is not how punishment is supposed to work in a sane society.