Mark Zuckerberg is firing back at Tim Cook.
The Facebook CEO defended his company's business model in an interview published by Vox on Monday, arguing that recent criticism from his counterpart at Apple was unfounded.
Cook recently called for increased regulation of social media, and questioned the practice of monetizing user data on free platforms by selling ads that allow advertisers to target specific groups.
"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 told Vox in response to a question about Cook's criticism.
"The reality here is that if you want to build a service that helps connect everyone in the world, then there are a lot of people who can't afford to pay," he added. "Having an advertising-supported model is the only rational model that can support building this service."
Facebook has been under intense pressure after it admitted that Cambridge Analytica, a company that worked on President Donald Trump's 2016 campaign, had accessed and improperly stored a huge trove of its user data.
Cook was asked last month how he would handle the crisis.
"I wouldn't be in this situation," the Apple CEO told reporters from Recode and MSNBC.
"The truth is, we could make a ton of money if we monetized our customer - if our customer was our product," he said. "We've elected not to do that."