Ars [1] has the 2 direct links you will need to opt out. These appear to be missing from the ExtremeTech article.<p>[1] - <a href="https://arstechnica.com/tech-policy/2021/03/t-mobile-will-tell-advertisers-how-you-use-the-web-starting-next-month/" rel="nofollow">https://arstechnica.com/tech-policy/2021/03/t-mobile-will-te...</a>
T-Mobile is 1) being very open about selling your data and 2) giving you fairly easy ways to opt-out in advance. Like it or not, your data is an asset -- that's just the age we live in, but at least T-Mobile is giving you some control over its use.
Also discussed here 2 days ago:<p><a href="https://news.ycombinator.com/item?id=26403614" rel="nofollow">https://news.ycombinator.com/item?id=26403614</a>