This post was written by EFF fellow Miranda McClellan.

Teens between the ages of  13 and 17 are being tracked across the internet using identifiers known as Advertising IDs. When children turn 13, they age out of the data protections provided by the Children’s Online Privacy Protection Act (COPPA). Then, they become targets for data collection from data brokers that collect their information from social media apps, shopping history, location tracking services, and more. Data brokers then process and sell the data. Deleting Advertising IDs off your teen’s devices can increase their privacy and stop advertisers collecting their data.

What is an Advertising ID?

Advertising identifiers – Android's Advertising ID (AAID) and Identifier for Advertising (IDFA) on iOS – enable third-party advertising by providing device and activity tracking information to advertisers. The advertising ID is a string of letters and numbers that uniquely identifies your phone, tablet, or other smart device.

How Teens Are Left Vulnerable

In most countries, children must be over 13 years old to manage their own Google account without a supervisory parent account through Google Family Link. Children over 13 gain the right to manage their own account and app downloads without a supervisory parent account—and they also gain an Advertising ID.

At 13, children transition abruptly between two extremes—from potential helicopter parental surveillance to surveillance advertising that connects their online activity and search history to marketers serving targeted ads.

Thirteen is a historically significant age. In the United States, both Facebook and Instagram require users to be at least 13 years old to make an account, though many children pretend to be older. The Children’s Online Privacy Protection Act (COPPA), a federal law, requires companies to obtain “verifiable parental consent” before collecting personal information from children under 13 for commercial purposes.

But this means that teens can lose valuable privacy protections even before becoming adults.

How to Protect Children and Teens from Tracking

 Here are a few steps we recommend that protect children and teens from behavioral tracking and other privacy-invasive advertising techniques:

• Delete advertising IDs for minors aged 13-17.
• Require schools using Chromebooks, Android tablets, or iPads to educate students and parents about deleting advertising IDs off school devices and accounts to preserve student privacy.
• Advocate for extended privacy protections for everyone.

How to Delete Advertising IDs

 Advertising IDs track devices and activity from connected accounts. Both Android and iOS users can reset or delete their advertising IDs from the device. Removing the advertising ID removes a key component advertisers use to identify audiences for targeted ad delivery. While users will still see ads after resetting or deleting their advertising ID, the ads will be severed from previous online behaviors and provide less personally targeted ads.

Follow these instructions, updated from a previous EFF blog post:

On Android

With the release of Android 12, Google began allowing users to delete their ad ID permanently. On devices that have this feature enabled, you can open the Settings app and navigate to Security & Privacy > Privacy > Ads. Tap “Delete advertising ID,” then tap it again on the next page to confirm. This will prevent any app on your phone from accessing it in the future.

The Android opt out should be available to most users on Android 12, but may not be available on older versions. If you don't see an option to "delete" your ad ID, you can use the older version of Android's privacy controls to reset it and ask apps not to track you.

On iOS

Apple requires apps to ask permission before they can access your IDFA. When you install a new app, it may ask you for permission to track you.

Select “Ask App Not to Track” to deny it IDFA access.

To see which apps you have previously granted access to, go to Settings > Privacy & Security > Tracking.

In this menu, you can disable tracking for individual apps that have previously received permission. Only apps that have permission to track you will be able to access your IDFA.

You can set the “Allow apps to Request to Track” switch to the “off” position (the slider is to the left and the background is gray). This will prevent apps from asking to track in the future. If you have granted apps permission to track you in the past, this will prompt you to ask those apps to stop tracking as well. You also have the option to grant or revoke tracking access on a per-app basis.

Apple has its own targeted advertising system, separate from the third-party tracking it enables with IDFA. To disable it, navigate to Settings > Privacy > Apple Advertising and set the “Personalized Ads” switch to the “off” position to disable Apple’s ad targeting.

Miranda McClellan served as a summer fellow at EFF on the Public Interest Technology team. Miranda has a B.S. and M.Eng. in Computer Science from MIT. Before joining EFF, Miranda completed a Fulbright research fellowship in Spain to apply machine learning to 5G networks, worked as a data scientist at Microsoft where she built machine learning models to detect malware, and was a fellow at the Internet Society. In her free time, Miranda enjoys running, hiking, and crochet.

At EFF, Miranda conducted research focused on understanding the data broker ecosystem and enhancing children’s privacy. She received funding from the National Science Policy Network.