You will not see a more purely terrifying movie this year than "Zero Days," a documentary from Alex Gibney ("Enron: The Smartest Guys in the Room," "Going Clear," "We Steal Secrets"), one of my favorite filmmakers. He spoke to journalists along with Eric Chien and Liam O'Murchu, two of the film's most important figures, the men who discovered what they dubbed the Stuxnet computer virus, which turned out to have been developed by the Unites States and Israeli governments to unleash on the...