Mark Zuckerberg is not happy with Apple, or at least, with statements that CEO Tim Cook made about online advertising a few months ago. In a recent TIME Magazine feature, Zuckerberg was quoted disagreeing substantially with points that Cook has made in the past about free web services.

The TIME feature, titled “Inside Mark Zuckerberg’s Plan to Wire the World,” was mostly about the Facebook CEO’s mission to put people all over the world on the internet – even in the poorest of third-world countries. However, the article did include Zuckerberg’s rebuttal to points that Cook made in September, after a hack of Apple’s iCloud service exposed private nude photographs of numerous celebrities.

After the hack, Cook posted an open letter on the Apple site to reassure users about “Apple’s commitment to your privacy.” In the post, Cook defended his company’s privacy policies by indirectly attacking companies like Facebook and Google for offering “free” web services with major strings attached. Ostensibly, those strings are sacrifices of privacy. Since free web services need to be monetized by advertising, and since Google, Facebook, and other companies collect information on their users to sell to advertisers, users end up paying for free services with their own private information.

Cook described it this way: “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.” And he has a point: Facebook has come under fire in the past for collecting information about users in order to formulate targeted ads. What Cook is suggesting is that such practices are a gross invasion of user privacy, and are not in the best interest of the customer.

Zuckerburg does not see things in the same light.

“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,” he told TIME. “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!”

The argument between the two corporate titans essentially boils down to differences in customer service ideology. Do you offer customers a free product and ask them to deal with a few advertisements. Or do you charge a lot of money upfront for the product with the understanding that advertising is not part of the deal? Neither ideology is really right or wrong, which is why Cook and Zuckerberg will probably never see eye to eye.