Geoff Hinton on a show called The Agenda (starting around 9:40):

Interviewer: How many years away do you think we are from a neural network being able to do anything that a brain can do?

Hinton: …I don’t think it will happen in the next five years but beyond that it’s all a kind of fog.

Interviewer: Is there anything about this that makes you nervous?

Hinton: In the very long run, yes. I mean obviously having… [AIs] more intelligent than us is something to be nervous about. It’s not gonna happen for a long time but it is something to be nervous about.

Interviewer: What aspect of it makes you nervous?

Hinton: Will they be nice to us?