People like their technology, so many tend to ignore the notion that the machines could take over. Yet I bet it is in the back of everyone's mind. The smarter the machine the more likely it is to become aware in some form and decide humans are flawed.
It doesn't have to be a Terminator or Sentinel type deal. All it would take is a machine that turned off all the lights, water, etc. and much of the world would be thrown into turmoil. Do you fear the machines?