Data collected by analytics firm Flurry reveals that only 4% of the iPhone users in the United States have enabled app tracking after updating their device to iOS 14.5. The figures are based on a sample size of 2.5 million daily mobile active users.

Worldwide, the numbers jump to 12%, with a sample userbase of 5.3 million. This means that an overwhelming majority of iPhone users are not allowing apps to track them across apps and services.

With the release of iOS 14.5, Apple introduced App Tracking Transparency that requires developers to show a prompt asking for user permission before tracking them across apps and services. App Tracking Transparency is expected to have a negative effect on ad revenues, with Facebook calling this change devasting for small businesses.

In its app tracking dialog box, Facebook says collecting user data activity allows it to keep Facebook and Instagram free of charge. On its part, Apple has made it clear that developers cannot lure users into granting them tracking permissions by using unethical techniques. This includes offering them incentives, displaying a custom message that looks similar to the system alert, use a visual cue to bring attention to the “Allow” button, and more. Doing any of this will result in the app being banned from the App Store.

Read: App Tracking Transparency in iOS 14.5 Explained

The numbers paint a worrying picture for advertisers who primarily rely on tracking users across ads and services to show targeted ads and increase their revenues. There were concerns in the advertising industry that most users would opt out of ad tracking, which is what the numbers from Flurry show.

Have you disabled App Tracking for all apps on your iPhone? Or do you decide on a per-app basis? Drop a comment and let us know!