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.

At the time, American legislators saw how concentrated power over the flow of information allowed a regime hostile to the public interest to master the democratic process and then destroy it by strategic use of misinformation. They also saw how the intent of this misinformation was to spread the view that the only solution to a national crisis was to grant its purveyors absolute power. So they made that impossible in the United States by preventing the aggregation of private power over the flow of information in the first place.

The primary legislative means by which this was done was the Communications Act of 1934, which created the Federal Communications Commission and prohibited concentrated ownership of radio stations and newspapers within and across geographic markets. In 1936, Congress also passed the Robinson-Patman Act, designed to prevent concentration within the supply chain of any industry and thus keep independent operators in business.

These policies were explicitly designed to prevent the concentration of power in private hands, especially power over the flow of information, because legislators worried that would set the stage for political disaster. Platform monopolies had to be ripped out at the root, lest the keys to the information kingdom fall into the wrong hands.

The last forty years, however, have seen a backlash against this precautionary approach to the accretion of private power. Consolidation and monopolization have increasingly been permitted on grounds of economic efficiency — the idea being that giants across sectors would realize economies of scale that could then be passed along to consumers in the form of lower prices and greater varieties and choices. Rather than snuffing out the threat of consolidated power by regulation and competition, the regulation itself became perceived as the threat, and so it was rolled back. In the information space, this happened most prominently with the Telecommunications Act of 1996, explicitly designed to retreat from the heavy restrictions on private actors merging and operating in concert that had been in place since the 1934 regime.

So now we have Facebook and a few other tech-sector behemoths straddling the flow of information like a colossus, deciding what will be permitted to flow beneath its legs and from where and to whom it will go. And it turns out that consumers like seeing things they agree with and propagate those things to the like-minded. Sources of fake news have become increasingly sophisticated — for instance, by printing their messages within images, which are harder to search and screen than plain text.

That is how the idea that a pizzeria is hiding a child sex-trafficking ring run by Democratic Party insiders can morph from a crazy fake story to a man with an automatic weapon in a room full of diners on a Sunday afternoon. Or to a xenophobic strongman parlaying a minority vote in a contested election into absolute power over all branches and levels of government.

Silicon Valley’s solution to the crisis of fake news is apparently to cooperate in selecting what to ban by algorithm — in other words, further industry consolidation, further concentration of power, more obscure and unaccountable decisions by the powerful. This is the tech-sector equivalent of a shoulder shrug, of social media billionaires fiddling while the republic burns.

Senator Joseph Robinson and Congressman Wright Patman, progenitors of the Robinson-Patman Act, had the right idea: make sure the power isn’t concentrated to begin with by making sure that private gatekeepers like Facebook do not get to decide who sees what from whom, for whatever reasons they want. That is a threat to democracy that cannot be underestimated.