T-Mobile bills itself as the "un-carrier," but don't ever take a corporation at its made-up word. According to new changes to its privacy policy, the carrier (no "un") is automatically enrolling its 100+ million customers in a targeted advertising program, selling their web and app usage data to partners. Customers can opt out, but the default will be opt-in starting on April 26th.

The Wall Street Journal reports on the change, buried deep in T-Mobile's privacy policy. The relevant changes were published on February 23rd:

However, starting April 26, 2021, T-Mobile will begin a new program that uses some data we have about you, including information we learn from your web and device usage data (like the apps installed on your device) and interactions with our products and services for our own and 3rd party advertising, unless you tell us not to.

T-Mobile has helpfully disabled copy and paste on that page, by the way.

The sources from which T-Mobile is collecting data include network traffic, app usage, and "information from financial institution and credit agencies." The data is not tied directly to names or account numbers, but when combined with advertising identifier tags, it still gets fairly specific in its association with single users. This is the kind of thing Google is trying to phase out, at least on the desktop version of Chrome. Elsewhere in the privacy policy, T-Mobile lays out a fairly typical system of sharing advertising data with unspecified third parties, a common (and lucrative) practice in modern tech.

To be clear: T-Mobile is very much in line with the rest of the industry here, it's only its years-long PR campaign of consumer advocacy that makes it grate on the nerves. If you'd like to avoid having your data shared with advertisers, you'll have to go to this page (while logged into your account) and change the setting manually.