The shooting at the Comet Pizzeria in Washington, DC last weekend brought the subject of fake news to national attention. The gunman was “self-investigating” the preposterous claim that Hillary Clinton and John Podesta operated a child sex ring out of the restaurant — something that a right-wing propagandist concocted out of the information that the restaurant hosted a Clinton campaign fundraiser.

So is this story just about a single nutty conspiracist, of the kind you’re bound to find in a country of 330 million people with an excessive love of automatic weaponry? Sadly, not at all — fake news is a real threat. Information is powerful because it motivates people to action. No one understood this better than Joseph Goebbels, the Nazi propaganda minister who fanned the flames of anti-Semitism and xenophobia with a torrent of offensive nonsense — most prominently, the staged burning of the Reichstag in 1933 and the subsequent framing of a Communist agitator, which led directly to the German parliament granting absolute power to the Nazi regime in a fit of “national security” hysteria.

Watching this unfold across the Atlantic, Congress eventually took steps to make sure it would never happen here. We had our own rabble-rousing, xenophobic propagandists: the rabid anti-Semite Father Charles Coughlin is the name most often repeated now. And we had our own financial crisis and mass unemployment, conditions under which established authority is discredited and the populace tends to look outside the mainstream for solutions to their problems.