The comedian eviscerated the CEO on Thursday in a blistering speech delivered to the Anti-Defamation League, calling him out for running the "biggest propaganda machine in history."
In a 25-minute talk after accepting the League's International Leadership Award, he slammed the social media giant for allowing hate speech, conspiracy theories and lies to be spread, claiming both Adolf Hitler and Joseph Goebbels would have been big fans.
The "Ali G" star was gunning for the "Silicon Six" — Jack Dorsey at Twitter, Sundar Pichai at Google, Sergey Brin and Larry Page at parent company Alphabet, and Susan Wojcicki (Brin's ex sister-in-law) at YouTube — but reserved most of his ammo for Zuckerberg.
"All this hate and violence is being facilitated by a handful of internet companies that amount to the greatest propaganda machine in history," he said.
He accused Facebook of helping perpetuate "the oldest conspiracy theory in history: the lie that Jews are somehow dangerous."
Cohen accepted that while half of his comedy may be juvenile (and the other half puerile), his formerly secret alter egos Borat, Bruno and Ali G had caused people to drop their guard and expose their real prejudices.
Highlighting the dangers of misinformation, he recalled the final episode of his show "Who Is America" in which he convinced a man of a plot to turn babies transgender using a chemical in diapers; he then convinced the same man to plant what he believed were real explosives on three people at a women's march, before trying to detonate them.
"Voltaire was right when he said: those who can make you believe absurdities, can make you commit atrocities," he quoted.
"This can't possibly be what the creators of the internet had in mind?" he said, calling for a "fundamental rethink of social media, and how it spreads hate, conspiracies and lies."
Mark Zuckerberg has argued strongly against the regulation of social media, claiming it hampers free speech; his arguments, Cohen said — excusing his French — were "bullshit".
"Freedom of speech is not freedom of reach," he said. "Sadly there will always be racists, misogynists, anti-Semites, and child abusers. But I think we can all agree that we should not be giving bigots and pedophiles a free platform to amplify their views and to target their victims."
He compared Zuckerberg's argument that regulations "pull back on free expression" to a Neo-Nazi goosestepping into a restaurant, threatening customers and demanding Jews be killed, while the owner is required to offer him an elegant eight-course meal.
"The owner has every legal right — and indeed I would argue a moral obligation — to kick that Nazi out. And so do these internet companies."
He said the Silicon Six — all Americans, all billionaires, all unelected — who care more about boosting their share-price than protecting democracy, should not be allowed impose their vision on the rest of the world, unaccountable to any government and acting like they are above the reach of law.
"This is ideological imperialism. It's like we are living in the Roman Empire, and Mark Zuckerberg is Caesar," he said, and couldn't help throwing in a little dig: "At least that would explain his haircut."
"If you pay them, Facebook will run any political ad you want - even if it's a lie," he said. "And they will even help you micro-target those lies to their users, for maximum effect."
"Under this twisted logic, if Facebook was around in the 1930s, it would have allowed Hitler to post 30 second ads on his solution to the Jewish problem."
Cohen claimed social media should be defined as publishers, and should have to uphold the same standards and practices as TV, cinema and magazines are forced to.
He called on Facebook to hire enough monitors to fact-check content before it is allowed be disseminated. "When ads are false give back the money and don't publish them," he demanded.
He also called for a delay before content is published, to prevent the likes of the "snuff film" created during the New Zealand mosque massacre in March.
"It's pretty clear they cannot regulate themselves," he said of the internet giant CEOs, pointing out that in any other industry, if a defective product causes harm, the company boss is held accountable.
"Your product is defective," he announced to Zuckerberg. "You need to fix it, no matter how much it costs."
"Maybe fines are not enough," he added. "Maybe its time to tell Mark Zuckerberg and the CEOs of these companies, you already allowed one foreign power to interfere in our elections. You already facilitated one genocide in Myanmar. Do it again, and you go to jail."