Mark Zuckerberg and Tim Cook have had a rivalry for years. Here’s the latest in the back and forth between Apple and Meta.

In September 2014, Cook gave an in-depth interview with Charlie Rose that touched on a range of topics, including privacy.

During the interview — which took place in the weeks following the infamous leaks of multiple female celebrities' nude photos stored on their iCloud accounts — Cook espoused Apple's commitment to privacy while denouncing the business models of companies like Google and Facebook. 

"I think everyone has to ask, how do companies make their money? Follow the money," Cook said. "And if they're making money mainly by collecting gobs of personal data, I think you have a right to be worried. And you should really understand what's happening to that data."  

Shortly after, Cook reiterated his stance in an open letter on Apple's dedicated privacy site. 

"A few years ago, users of Internet services began to realize that when an online service is free, you're not the customer. You're the product," Cook wrote. 

In an interview with Time later that year, Zuckerberg was reportedly visibly irritated by Cook's assertions. 

"A frustration I have is that a lot of people increasingly seem to equate an advertising business model with somehow being out of alignment with your customers," Zuckerberg told Time's Lev Grossman. "I think it's the most ridiculous concept. What, you think because you're paying Apple that you're somehow in alignment with them? If you were in alignment with them, then they'd make their products a lot cheaper!"

In 2018, a whistleblower revealed that consulting firm Cambridge Analytica harvested user data without consent from 50 million users. 

During an interview with Kara Swisher and Chris Hayes in the months following, Cook was asked what he would do if he was in Zuckerberg's shoes.

Cook responded: "What would I do? I wouldn't be in this situation."

Cook said that Facebook should have regulated itself when it came to user data, but that "I think we're beyond that here." He also doubled down on his stance that Facebook considers its users its product. 

"The truth is, we could make a ton of money if we monetized our customer — if our customer was our product," Cook said. "We've elected not to do that."

"You know, I find that argument, that if you're not paying that somehow we can't care about you, to be extremely glib. And not at all aligned with the truth," Zuckerberg said during an interview on The Ezra Klein Show podcast.

He refuted the idea that Facebook isn't focused on serving people and once again criticized the premium Apple places on its products. 

"I think it's important that we don't all get Stockholm Syndrome and let the companies that work hard to charge you more convince you that they actually care more about you," he said. "Because that sounds ridiculous to me."

In November 2018, The New York Times published a blockbuster report detailing the fallout from the Cambridge Analytica scandal. The Times reported that Cook's comments had "infuriated" Zuckerberg, who ordered employees on his management team who used iPhones to switch to Android. 

Soon after the report published, Facebook wrote a blog post refuting some of the reporting by The Times — but not the Zuckerberg-Cook feud. 

"Tim Cook has consistently criticized our business model and Mark has been equally clear he disagrees. So there's been no need to employ anyone else to do this for us," Facebook wrote. "And we've long encouraged our employees and executives to use Android because it is the most popular operating system in the world."

According to The Times, Zuckerberg asked Cook for his advice following the Cambridge Analytica scandal.

Cook told Zuckerberg Facebook should delete the user data his company collects from outside of its family of apps, which "stunned" Zuckerberg and was akin to Cook saying Facebook's business was "untenable," The Times reported.

During a company-wide meeting, Zuckerberg openly criticized Apple, saying it has a "unique stranglehold as a gatekeeper on what gets on phones," according to a report from BuzzFeed News. 

Zuckerberg also said that the App Store blocks innovation and competition and "allows Apple to charge monopoly rents," BuzzFeed reported. 

Apple has been facing antitrust scrutiny from Congress and has been strongly criticized by developers — most notably "Fortnite" creator Epic Games — for the 30% fee it takes from App Store purchases. In 2020, Facebook said Apple blocked an update to Facebook's iOS app that would have informed users about the fee Apple charges.

That version of Apple's smartphone operating system, iOS, made it so that iPhone app developers would need permission from users to collect and track their data. While this affects any company that makes iOS apps, it also has a direct impact on Facebook's advertising business: It uses data tracking to dictate which ads are served to users. 

In an August 2020 blog post, Facebook said it may be forced to shut down Audience Network for iOS, a tool that personalizes ads in third-party apps. 

"This is not a change we want to make, but unfortunately, Apple's updates to iOS 14 have forced this decision," Facebook said. 

The complaints from Facebook and other developers led Apple to temporarily delay the new privacy tools, saying it wanted to "give developers the time they need to make the necessary changes."

In the ads, Facebook argued that the changes would hurt small businesses that advertise on Facebook's platform.

"Without personalized ads, Facebook data shows that the average small business advertiser stands to see a cut of over 60% in their sales for every dollar they spend," the ad reads, which was posted by Twitter user Dave Stangis. 

Apple hit back, telling Business Insider that it was "standing up for our users." 

"Users should know when their data is being collected and shared across other apps and websites — and they should have the choice to allow that or not," an Apple spokesperson said.

Epic Games had accused Apple of violating antitrust laws and engaging in anticompetitive behavior regarding the App Store's fees and policies.

Facebook said it planned to help Epic with discovery for the trial. 

When discussing Facebook's suite of messaging apps during the company's fourth-quarter earnings call, Zuckerberg made a clear dig at Apple, saying the iPhone maker made "misleading" privacy claims. 

"Now Apple recently released so-called nutrition labels, which focused largely on metadata that apps collect rather than the privacy and security of people's actual messages, but iMessage stores non-end-to-end encrypted backups of your messages by default unless you disable iCloud," Zuckerberg said.

Zuckerberg went on to describe Apple as "one of our biggest competitors" and said that because Apple is increasingly relying on services to fuel its business, it "has every incentive to use their dominant platform position to interfere with how our apps and other apps work, which they regularly do to preference their own."

"This impacts the growth of millions of businesses around the world," he added.

During a speech at the European Computers, Privacy and Data Protection Conference the same week, Cook discussed business models that prioritize user engagement and rely on user data to make money. Though he didn't mention Facebook by name, Cook made several references that alluded to the platform.

"At a moment of rampant disinformation and conspiracy theories juiced by algorithms, we can no longer turn a blind eye to a theory of technology that says all engagement is good engagement — the longer the better — and all with the goal of collecting as much data as possible," Cook said.

The initiative, titled "Good Ideas Deserve to be Found," makes the case that personalized ads help Facebook users discover small businesses, particularly during the pandemic. 

"Every business starts with an idea, and being able to share that idea through personalized ads is a game changer for small businesses," Facebook said in a blog post announcing the theme. "Limiting the use of personalized ads would take away a vital growth engine for businesses."

During a podcast interview with Kara Swisher, Cook said that he believes society is in a privacy crisis and that he's been "shocked" that there's been pushback to the new feature to this degree. 

"We know these things are flimsy arguments," Cook told The Times. "I think that you can do digital advertising and make money from digital advertising without tracking people when they don't know they're being tracked."

Cook also said he doesn't view Facebook as a competitor, contrary to what Zuckerberg has said.

"Oh, I think that we compete in some things," Cook said. "But no, if I may ask who our biggest competitor are, they would not be listed. We're not in the social networking business."

"The impact of iOS overall as a headwind on our business in 2022 is on the order of $10 billion," then-Meta CFO David Wehner estimated in an earnings call that year.

Apple, for its part, said in January that it had "fully complied" with the injunction.

Apple released its Vision Pro headset in February, and Zuckerberg was quick to offer his critique of the competitor to Meta's Quest headsets.

"I have to say that before this, I expected that Quest would be the better value for most people since it's really good and like seven times less expensive, but after using [Vision Pro] I don't just think that Quest is the better value, it's the better product, period," Zuckerberg said in a video on Threads. "They have different strengths, but overall Quest is better for the vast majority of things that people use mixed reality for."

Zuckerberg says many people "assumed that Vision Pro would be higher quality because it's Apple and it costs $3,000 more."

"I know that some fanboys get upset whenever anyone dares to question if Apple's going to be the leader in a new category," he said. "But the reality is that every generation of computing has an open and a closed model. And yeah, in mobile, Apple's closed model won, but it's not always that way."

In Meta's first quarter earnings call in April, Zuckerberg said he didn't think AR glasses would find mainstream success without "full holographic displays."

"I still think that that's going to be awesome and is the long-term mature state for the product," he said. "But now, it seems pretty clear that there's also a meaningful market for fashionable AI glasses without a display."

Meta CTO Andrew Bosworth has also taken shots at Apple over its Vision Pro.

"As soon as I put the headset on, I can see what trade-offs they made and why they made them. And, perhaps definitionally, those aren't the trade-offs I would have made," he said.

Bosworth called the Vision Pro's motion blur "really distracting" and said the headset was "very uncomfortable to use."

Apple months ago rejected the possibility of integrating Meta's Llama AI chatbot into the iPhone because it doesn't consider Meta's privacy practices up to par, Bloomberg's Mark Gurman reported in June 2024, citing people with knowledge of the matter.

Apple has since announced a partnership with OpenAI for ChatGPT.