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AT&T Stops Attaching Tracking Files to Mobiles

Wait… AT&T was tracking you with hidden codes?

The secret codes in tracking files, known as ‘header enrichment,’ consist of strings of numbers and letters that are appended to all data traffic that is transmitted from the phone. The header enrichment codes are used to track customers’ website visits and also which apps they use in order to provide advertisers with targeting information. The codes don’t contain personal identity information per se, but because they are unique to each customer and are transmitted along with any personal identity information that a customer voluntarily provides – such as name, address or phone number – together they create a sort of digital fingerprint that could be exploited.

AT&T said it ended the tracking files because its test project has ended. But competing mobile operator Verizon has a similar tracking number system in place, which Twitter’s mobile advertising division uses to target ads.

If you want to know if your mobile carrier is tracking your device, visit this page on (go there from your mobile device) and click on the box that says ‘Does Your Phone Company Track You?’

Header enrichment technology was developed because traditional web cookies are a challenge for tracking apps on smartphones and tablets. The Open Mobile Alliance adopted an industry standard for injecting the codes in 2010. In response, Google has proposed an alternative Web protocol that prevents such header injections which, of course, the mobile industry is lobbying to defeat.

Avira’s security software for Android and iOS can scan your apps and emails for malware, and also block Trojans and stop Ransomware from restricting access to your data. Check out Avira Mobile Security for iOS or Avira Antivirus Security for Android for free protection.


PR & Social Media Manager @Avira.