Cook criticized Facebook last week during an interview with Recode's Kara Swisher and MSNBC's Chris Hayes, saying he "wouldn't be" in Zuckerberg's situation — hemorrhaging shareholder value and facing regulatory probes.
Zuckerberg came under fire over Facebook's privacy practices in the wake of revelations that Cambridge Analytica improperly gained access to data from more than 50 million user profiles. The profile information was used for targeted political ads.
Cook last week questioned the practice of monetizing user data on social platforms. Facebook executives have long said the service will always be free for users, but that such a model requires selling advertising based on anonymous user information.