Could Artificial Intelligence Ever Become A Threat To Humanity?

What is a plausible path (if any) towards AI becoming a threat to humanity? I don't think at AI will become an existential threat to humanity. I'm not saying that it's impossible, but we would have to be very stupid to let that happen. Others have claimed that we would have to be very smart to prevent that from happening, but I don't think it's true. If we are smart enough to build machine with super-human intelligence, chances are we will not be stupid enough to give them infinite power to destroy humanity.