Facebook and Apple are fighting. Your browsing history is in the middle.

Apple and Facebook will need each other in the long run because billions of people want their social media apps to work well on their phones and tablets. But first, the two tech giants in California have to solve a mockery that takes place in newspaper ads, industry rallies and potentially federal courts.

Facebook on Thursday aired its second full-page newspaper ad in as many days, attacking Apple’s plans to inform iPhone and iPad users when apps follow them online.

“Apple intends to launch a forced software update that will change the Internet as we know it – for the worse,” Facebook said in the ad.

It is a very personal and unusually personal battle between two companies that have a wide influence. At the heart of the battle is how the advertising-dependent part of the Internet will work in the years to come.

In the next few weeks, Apple plans to launch a new feature on its devices, which will alert people when an app like Facebook tries to “track your activity in other companies’ apps and websites.” People will have options such as “Ask the app not to follow” or “Allow”.

“Users should know when their data is being collected and shared in other apps and websites – and should be able to allow it or not,” Apple said in a statement. “Transparency of app tracking in iOS 14 does not require Facebook to change its approach to tracking users and creating targeted advertising, but simply gives users a choice.”

For Facebook, the possibility of many people banning tracking threatens one of the data streams that make its advertising business so profitable. Facebook uses data such as browsing history to show people the ads it is most likely to want to see and to show marketers that its ads are working.

“Apple’s move is not about privacy, it’s about profit,” Facebook said in a statement. He claims that Apple has something to gain if more of the internet becomes subscription-based, because Apple charges commissions from its app store.

The two companies, headquartered within a 15-minute drive, have been carefully surrounded for years. Apple CEO Tim Cook rejected Facebook for “collecting personal data,” while Facebook CEO Mark Zuckerberg rejected calling iPhones an expensive product for the world’s elite, not for the masses. Facebook encourages its employees to use rival Android devices.

Last year, Apple caused temporary disruption to Facebook by closing Facebook employees’ access to Facebook’s internal applications running on the iPhone. Apple has established that Facebook has improperly paid teenagers and others for their smartphone data.

Companies have radically different business models. Facebook earned $ 70 billion in advertising last year, almost its only source of revenue. Advertising sales are a small part of Apple’s $ 275 billion annual revenue, which comes primarily from device sales and app store commissions.

Apple said new tracking notifications will begin appearing in early 2021. Privacy groups such as the Electronic Frontier Foundation support them.

But Facebook is making a last-ditch effort to persuade Apple to return or compromise with industry standards. millions of small companies buying ads on Facebook and Instagram.

The latest announcement, on Thursday, claims that free online publishers will not be able to survive if Apple lets go, unless publishers charge subscriptions – from which Apple could reduce, thanks to the rules in its app store.

“Take your favorite cooking sites or sports blogs. Most of them are free, because they display advertisements “, said Facebook in its advertisement. “Changing Apple will limit their ability to run custom ads. To get to the end, many will have to start charging you subscription fees or adding more in-app purchases, making the internet much more expensive and reducing high-quality free content. “

Facebook has raised the prospect of antitrust lawsuits. In a blog post, he said he had pledged to provide information to a federal court in an ongoing lawsuit against Apple, filed by Epic Games, which is trying to reduce the fees it pays through the Apple app store.

“We believe that Apple is behaving anti-competitively by using its control over the App Store to benefit from their results to the detriment of application developers and small businesses. We continue to explore ways to address this concern, “Facebook said.

Facebook is battling antitrust complaints from states and the Federal Trade Commission, and both Zuckerberg and Cook have been compared to “emperors.”

Apple, for now, keeps its plans for tracking notifications and indicates a long record of advocacy for online privacy.

“We think it’s a simple matter of being in favor of our users,” Apple said.