Facebook (NASDAQ:FB) and Apple (NASDAQ:AAPL), never the best of tech industry friends, are at odds over the latter's upcoming update to the iPhone's operating system. In an official company blog post today, Facebook wrote that due to changes being implemented in iOS 14, "[o]ur ability to deliver targeted ads on iOS 14 will be limited."

"As a result, some iOS 14 users may not see any ads from Audience Network, while others may still see ads from us, but they'll be less relevant," the company said.

A woman using a smartphone.

Image source: Getty Images.

According to Facebook, this will probably mean that, along with the company, app developers will receive less advertising revenue.

A beta version of iOS 14 was released to developers earlier this week. Among its new and enhanced features is a set of anti-tracking measures that limit the ability of advertisers to zero in on a particular user and deliver highly tailored advertising.

Facebook is specifically concerned with its Audience Network advertising business. This allows the social media giant to deliver ads to its users through other apps that they've connected their Facebook identities to. The company doesn't break out the performance of Audience Network in its results; analysts believe its revenue could be in the billions of dollars annually.

Facebook did say that "in testing, we've seen more than a 50% drop in Audience Network publisher revenue when personalization was removed from mobile app ad install campaigns."

Apple hasn't yet officially responded to Facebook's claims.

The potential hit to Facebook's ad revenue wasn't affecting the company's stock on Wednesday. In late afternoon trading, it was up by 7% and had crossed the $300 level for the first time in its history. Apple was up by 1%.

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