First Stephen Hawking and Elon Musk expressed concern about artificial intelligence. Now Bill Gates joins the chorus.

I'm not making this up. A bunch of people including some top AI researchers are adding their signatures to an open letter urging everyone to keep AI research from careening into darkness and destroying the human race. Actually the letter just says researchers should focus only on doing good things with AI, and there is a link to a document (extremely tl;dr) that outlines what some of those things might be.