How worried should we be about artificial intelligence? Popular culture is rife with terrifying tales of insane or malevolent AI, from HAL-9000 in “2001” to Skynet in the “Terminator” films and the machines that turn human beings into living batteries in the “Matrix” movies. Rogue AI is a sci-fi cliche. But is it close to becoming a reality? Some 1,800 tech entrepreneurs, computer scientists…