Tesla CEO Elon Musk has been very vocal regarding his fears surrounding evil AI. He has called for regulatory oversight to ensure "we don't do something very foolish" when it comes to AI. 

And he's not afraid of hyperbole on the subject: "With artificial intelligence we are summoning the demon," Musk said at MIT's Aeronautics and Astronautics department's Centennial Symposium in 2014. 

Rosemary's Baby "If I were to guess what our biggest existential threat is, it’s probably that. So we need to be very careful with the artificial intelligence," Musk said in 2014. Paramount Pictures

But Facebook CEO Mark Zuckerberg says there's no reason to fear "evil" artificial intelligence.

After announcing his plan on Facebook to build an AI personal assistant, Zuckerberg took to the comments section to say that he's against the "fear-monger" statements made by folks like Tesla CEO Elon Musk about the potential for AI to turn evil.

"I think we can build AI so it works for us and helps us. Some people fear-monger about how AI is a huge danger, but that seems far-fetched to me and much less likely than disasters due to widespread disease, violence, etc.," he wrote on Facebook.

Zuckerberg's thoughts on AI differ from other Silicon Valley tech giants, who claim there is a good reason to fear AI turning evil.

In January 2015, the Future of Life Institute (FLI), a nonprofit dedicated to mitigating existential threats to humanity, released an open letter calling for research to keep AI beneficial. Stephen Hawking and Musk were two of dozens of big names in AI to sign the letter. At the time, Musk pledged to give $10 million in support of the research.

elon musk Patrick Fallon / Reuters

More than 16,000 researchers cosigned another FLI letter urging the United Nations to ban the production and use of autonomous weapons. Musk, Hawking, and Google director of research Peter Norvig are just a few that signed.

"I just think we should cautious about the advent of AI and a lot of the people that I know that are developing AI are too convinced that the only outcome is good," Musk said during his presentation in Paris over climate talks in December 2015.

"We need to consider potentially less good outcomes, and to be careful and really to monitor what's happening and make sure the public is aware of what's happening," he added.

Musk also announced the formation of OpenAI, a nonprofit research company, with the goal to "advance digital intelligence in the way that is most likely to benefit humanity as a whole" in December.

Musk co-chairs OpenAI with Y Combinator's Sam Altman who, like Zuckerberg, does not believe there is a reason to fear evil AI.

"That is so far in the future it's difficult to discuss and focus on," Altman told Tech Insider. "We can imagine near-term negative effects."