"The Facebook that exists today is not the Facebook that we founded in 2004," Chris Hughes, who started Facebook with Mark Zuckerberg in their Harvard dorm, told NBC News following the publication of his op-ed article on the same topic.
"And the one that we have today I think is far too big. It's far too powerful. And most importantly, its CEO, Mark Zuckerberg, is not accountable," Hughes said of his former business partner, whom he still called a "friend."
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"I have been friends with Mark and a lot of the other folks at Facebook for a long time. And you know, who knows? We may still be friends, we may not be friends. There are some kinds of friends that you can have disagreements with. And then there are some friends that you can't," Hughes said.
Hughes joins a growing chorus of privacy advocates and politicians from the right and the left, including Sen. Elizabeth Warren, D-Mass., a presidential candidate, and Sen. Ted Cruz, R-Texas, who have called for federal antitrust action against Facebook.
The mood in Washington has soured against the former tech darling in recent years following the leaks of millions of its users' personal information and the disclosure that its platform had been manipulated by Russian propagandists to spread misinformation and undermine democracy.
More than a dozen Congressional hearings have produced apologies from Zuckerberg, executives and lawyers, and commitments to prevent further harm, but watchdogs don't believe the company has gone far enough and argue that it is abusing its power.
In March, Warren said she would call for federal regulators to "unwind anti-competitive mergers" as president, including forcing Instagram and WhatsApp to once again spin off from Facebook. She also called for the separation of Whole Foods and Zappos from Amazon, and the ad network DoubleClick from Google.
Warren also called for internet platforms to be designated as utilities, which would make companies like Facebook subject to more lawsuits and fines if they run afoul of privacy law.
According to CNBC estimates, Zuckerberg and a small group of insiders control almost 70 percent of all voting shares in Facebook. Zuckerberg personally controls nearly 60 percent. If he quit as CEO tomorrow, he would still control the company through his stock ownership.
But Hughes said there's one power Zuckerberg won't exercise.
"I don't think that Mark Zuckerberg can fix Facebook," Hughes said. "I think only government can — by making the market more competitive, by breaking it up, and by creating these privacy restrictions."
Hughes called for the government to step in and take several drastic actions: First, reversing the mergers with Instagram and WhatsApp, which he said the FTC "incorrectly approved," spinning them out as private companies that would compete with Facebook. Second, creating a new agency to regulate technology in addition to the FTC.
He also said the courts should come up with guidelines for what qualifies as violent or hateful speech, "decisions that right now corporate executives are making on their own." The proposal echoed those of Warren and other Facebook critics.
Hughes said the issue was non-partisan, and cited the FTC's breakup of telecommunications giant AT&T under President Ronald Reagan as a precedent.
Though Zuckerberg himself has called for government regulation of the company, Hughes said he believes that the Facebook CEO wants to manage the process to be "friendly to Facebook's corporate interests and corporate objectives" and would stop short of the breakup Hughes believes is needed.