There's been some talk about T-Mobile selling app usage data to third parties:<p>https://www.adexchanger.com/mobile/t-mobile-rebrands-its-ad-biz-and-navigates-the-perilous-line-between-programmatic-and-privacy/<p>https://www.phonearena.com/news/t-mobile-app-insights-selling-user-data_id140978<p>The question is: how is this data gathered? Is it via a hidden service in the OS? Or by monitoring network traffic? The privacy policy osn't if much help in this regard:<p>https://www.t-mobile.com/privacy-center/our-practices/advertising-solutions-privacy-notice<p>Even though it claims to describe "how we collect, use, and share personal data", it does not at all answer the question of "how do they collect the data".<p>So... how do they collect the data?