New York CNN Business  — 

Elon Musk on Monday claimed that Apple has “threatened” to pull Twitter from its iOS app store, a move that could be devastating to the company Musk just acquired for $44 billion.

“Apple (AAPL) has also threatened to withhold Twitter from its App Store, but won’t tell us why,” Musk said in one of several tweets Monday taking aim at Apple (AAPL) and its CEO for alleged moves that could undermine Twitter’s business.

In another tweet, Musk claimed that Apple has mostly stopped advertising on Twitter. “Do they hate free speech in America,” he said, in an apparent reference to his oft-stated desire to bolster his idea of free speech on the platform. “What’s going on here [Apple CEO Tim Cook]?” Musk added in a follow-up tweet. He also criticized Apple’s size, claimed it engages in “censorship,” and called out the 30% transaction fee Apple charges large app developers to be listed in its app store.

The tweetstorm highlights the tenuous relationship between Musk and Apple, which along with Google serves as the major gatekeepers for mobile applications. Long before taking over Twitter, the Tesla CEO said that when the car company was struggling, he considered selling the company to Apple, but that Cook refused to take a meeting with him.

Removal from Apple’s app store, or that of Google, would be detrimental to Twitter’s business, which is already struggling with a loss of advertisers following Musk’s takeover and a rocky initial attempt at expanding its subscription business.

Apple did not immediately respond to a request for comment on Musk’s tweets. The company has previously shown it’s willing to remove apps from its app store over concerns about their ability to moderate harmful content or if they attempt to circumvent the cut Apple takes from in-app purchases and subscriptions.

In January 2021, Apple removed Parler, an app popular with conservatives, including some members of the far right, from its app store following the US Capitol attack over concerns about the platform’s ability to detect and moderate hate speech and incitement. Parler was returned to Apple’s app store three months later after updating its content moderation practices.

In its official app store review guidelines, Apple lists various safety parameters that apps must adhere to in order to be included in the store, including an ability to prevent “content that is offensive, insensitive, upsetting, intended to disgust, in exceptionally poor taste, or just plain creepy” such as hate speech, pornography and terrorism. “If you’re looking to shock and offend people, the App Store isn’t the right place for your app,” the guidelines state.

Various civil society groups, researchers and other industry watchers have raised concerns about Twitter’s ability to effectively moderate harmful content and maintain the platform’s safety following widespread layoffs and mass employee exits at the company. Musk has also claimed he wants to amplify “free speech” on the platform and has begun to restore some accounts that were previously banned or suspended for repeatedly violating Twitter’s rules. Musk himself has shared a conspiracy theory and several other controversial tweets since taking over as Twitter’s owner.

Musk, long a prolific and antagonistic tweeter, has not let up at all since taking over the company. And what it may have lost in revenue, he has claimed it has made up for in engagement. Part of the strategy appears to be relentlessly taking aim at enemies, either of him personally or of “free speech.”

In an interview with CBS earlier this month, Cook was asked whether there are any ways in which Twitter could change that would cause Apple to remove it from the app store. “They say that they’re going to continue to moderate and so … I count on them to do that,” Cook responded. “Because I don’t think that anybody really wants hate speech on their platform. So I’m counting on them to continue to do that.”

In an op-ed published in the New York Times last week, Twitter’s former head of trust and safety, Yoel Roth, who left the company earlier this month, suggested that Twitter had already begun to receive calls from app store operators following Musk’s takeover. Roth said the company’s failure to adhere to Google and Apple’s app store rules could be “catastrophic.”

And last weekend, the head of Apple’s app store, Phil Schiller, deleted his Twitter account.

While the state of Apple and Twitter’s relationship is unclear, the iPhone maker was running Black Friday ads on the platform as recently as last Thursday, according to posts viewed by CNN.

Many companies have pulled back on digital ad spending in recent months as the economy declined, and Twitter has likely always only been a small portion of Apple’s ad budget. Apple’s impact on Twitter, however, could be much more significant, including if Musk succeeds in shifting its core business to being more reliant on subscription revenue, and potentially has to pay a 30% cut to Apple.

In one tweet Monday, Musk asked his nearly 120 million followers if they know “Apple puts a secret 30% tax on everything you buy through their App Store?” In another tweet, he posted a picture of a highway exit: one lane headed toward “pay 30%,” the other pointed toward “go to war.” An old car labeled “Elon” skidded toward the latter.