Data sales begin April 26 unless you opt out; T-Mobile claims it'll be anonymous.
Ars Technica Reported on it: https://arstechnica.com/tech-policy/2021/03/t-mobile-will-tell-advertisers-how-you-use-the-web-starting-next-month/
Ars Technica Reported on it: https://arstechnica.com/tech-policy/2021/03/t-mobile-will-tell-advertisers-how-you-use-the-web-starting-next-month/