Maybe the trouble started with the AI billionaire and the Silicon Valley chaos that followed talk of his infidelity, including with an alleged Chinese spy. Or maybe it was the Microsoft outage that, depending on how you looked at it, either cast millions of frustrated workers adrift or spared them from a daily, unrelenting electronic avalanche. But by Friday afternoon, when U. S. authorities suddenly ordered every plane across the country to land immediately, it felt to many that something was...