In a keynote address to the Anti-Defamation League, entertainer Sacha Baron Cohen calls the platforms created by Facebook, Google, Twitter, and other companies “the greatest propaganda machine in history” and blasts them for allowing hate, bigotry, and anti-Semitism to flourish on these services.

Think about it. Facebook, YouTube and Google, Twitter and others — they reach billions of people. The algorithms these platforms depend on deliberately amplify the type of content that keeps users engaged — stories that appeal to our baser instincts and that trigger outrage and fear. It’s why YouTube recommended videos by the conspiracist Alex Jones billions of times. It’s why fake news outperforms real news, because studies show that lies spread faster than truth. And it’s no surprise that the greatest propaganda machine in history has spread the oldest conspiracy theory in history- — the lie that Jews are somehow dangerous. As one headline put it, “Just Think What Goebbels Could Have Done with Facebook.”

On the internet, everything can appear equally legitimate. Breitbart resembles the BBC. The fictitious Protocols of the Elders of Zion look as valid as an ADL report. And the rantings of a lunatic seem as credible as the findings of a Nobel Prize winner. We have lost, it seems, a shared sense of the basic facts upon which democracy depends.

When I, as the wanna-be-gansta Ali G, asked the astronaut Buzz Aldrin “what woz it like to walk on de sun?” the joke worked, because we, the audience, shared the same facts. If you believe the moon landing was a hoax, the joke was not funny.

When Borat got that bar in Arizona to agree that “Jews control everybody’s money and never give it back,” the joke worked because the audience shared the fact that the depiction of Jews as miserly is a conspiracy theory originating in the Middle Ages.

But when, thanks to social media, conspiracies take hold, it’s easier for hate groups to recruit, easier for foreign intelligence agencies to interfere in our elections, and easier for a country like Myanmar to commit genocide against the Rohingya.