The source – theverge.com
Google said it will hide the unique identifiers of Android devices (IDs) from app developers if the user has not agreed to personalize ads. Instead of an identifier, developers will see a string of zeros.
The update will take effect by the end of 2021 for Android 12 devices, and will roll out to all devices next year. The update will give users more control over their personal data and increase their security and privacy.
Android users can now opt out of ad personalization in settings, but technically, developers still have the ability to track unique user IDs to measure ad performance. For example, thanks to the ID, you can track who clicked on the ad and what action they took after switching to the landing page.
In July Google will release plans for an alternative developer solution to track ad performance for opt-out users.