Facebook’s line of attack against Apple mirrors that of other companies. Apple has near-absolute power over its app store, deciding which apps make the cut and which don’t, and cut its revenue by 30 percent. In 2019, Spotify, the streaming music company, filed a complaint with European regulators, accusing Apple of using its App Store to squeeze companies that compete with its services, including Apple Music.

In August, Epic Games, the inventor of the popular game Fortnite, sued Apple for forcing developers to use its payment systems and accused Apple of engaging in anti-competitive practices in the App Store. Facebook has announced that it will provide information to Epic in its lawsuit so that the court can understand “the unfair guidelines Apple is imposing.” Epic, Spotify, and others have also organized a nonprofit group, the Coalition for App Fairness, to push for changes in app stores and “protect the app economy.”

This week, Mr. Zuckerberg and Mr. Cook continued barbed trading.

On Wednesday, Zuckerberg said in a conference call with Wall Street analysts that he sees Apple as one of Facebook’s “biggest competitors”. He cited iMessage, Apple’s iPhone-specific SMS service, as an existential threat to Facebook’s social networking services.

He added that Apple “had every incentive to use their dominant platform position” to disrupt Facebook and other apps. Apple regularly treats its own apps in the App Store cheaper, he said.

On Thursday, Mr Cook said at a European data protection conference that Apple’s new tracking capabilities for apps and the new privacy labels were required because of a “data industrial complex” that has threatened consumer privacy.

“It seems that no information is too private or too personal to be monitored, monetized and summarized into a 360-degree view of your life,” Cook said. “Some may think that sharing this level of information is worth it for more targeted ads. Many others, I suspect, won’t. “