Mark Zuckerberg doubles down defending A.I. after Elon Musk says his understanding is 'limited'

Earlier this month, Musk delivered a scary message while speaking to the National Governors Association: "I have exposure to the most cutting edge AI, and I think people should be really concerned by it. AI is a fundamental risk to the existence of human civilization." On Sunday, Zuckerberg was dismissive of such warnings. "I think people who are naysayers and try to drum up these doomsday scenarios -- I just, I don't understand it. It's really negative and in some ways I actually think it is pretty irresponsible," he says.