Facebook Inc. FB 0.04% Chief Executive Mark Zuckerberg has groused for years that Apple Inc. AAPL 0.18% and its leader, Tim Cook, have too much sway over the social-media giant’s business. In 2018, his anger boiled over. In private, Mr. Zuckerberg was even harsher. “We need to inflict pain,” he told his team, for treating the company so poorly, according to people familiar with the exchange. Apple CEO Tim Cook at Apple’s Worldwide Developer Conference in 2018. Photo: Justin Sullivan/Getty Images It wasn’t the first time—or the last—that Mr. Cook’s comments and actions would leave Mr. Zuckerberg seething and, at times, plotting to get back at Apple. The escalation of grievances erupted late last month in a rare public tit-for-tat between the two tech giants that laid bare the simmering animosity between their leaders, who exchanged jabs about privacy, app-tracking tools and, ultimately, their dueling visions about the future of the internet. Apple has positioned itself as the protector of digital privacy, upholding a greater good, while often leveling criticisms at Facebook’s business model—without naming the company. All of that grates on Facebook, » Read More












