T-Mobile prides itself on being the “Un-carrier,” but its latest advertising move is decidedly “Carrier” and threatens its users’ privacy.

T-Mobile’s turnaround has been so successful that it will be studied in business school for years to come. Once the fourth-largest carrier, and facing major challenges, the company moved into second place after surpassing Sprint for third and then buying them out. T-Mobile now finds itself as a leader in 5G and the company to beat in the wireless industry.

Much of that success stems from its Un-carrier status, with an emphasis on giving customers what they want. Unlimited data, taxes and fees included in the final price, international texting and data, as well as free calling to and from Canada and Mexico are just a few of the features the magenta carrier pioneered or reintroduced to the market.

The company’s customer-focused approach makes its latest decision all the more difficult to understand, as it is automatically opting customers into targeted advertising that will use their data.

Under T-Mobile’s personalized ads program, we use and analyze data from things like device and network diagnostic information (Android users only), apps on your device, and broadband information. This data helps us understand more about user interests (e.g., sports enthusiast, loves cooking, etc.). Using this information, we create groups known as “audience segments,” which may be used by T-Mobile or sold to third parties to make ads more relevant to you. When we sell audience segments, we do not sell information that directly identifies customers, like name, address, or email. Rather, audience segments are associated with mobile advertising IDs, which are long set of numbers and letters. For example, this might say something like “2drdn43np2cMapen084″ is a sports enthusiast.” Take a look at our Advertising and Analytics article and T-Mobile privacy policy for details.

A spokeswoman told The Wall Street Journal that the company had “heard many say they prefer more relevant ads so we’re defaulting to this setting.”

The company claims that the information is not identifiable and can’t be linked to a specific user. Unfortunately, that claim doesn’t even begin to hold water.

“It’s hard to say with a straight face, ‘We’re not going to share your name with it,’ ” Aaron Mackey, a lawyer for the San Francisco-based Electronic Frontier Foundation, told the WSJ. “This type of data is very personal and revealing, and it’s trivial to link that deidentified info back to you.”

While Verizon and AT&T both sell customer data to advertisers, they both take the extra step of pooling the data together to make it much more difficult, if not impossible, to identify specific profiles. Both companies also have more detailed targeted ad programs, like T-Mobile’s, that share far more personal data. However, these programs are opt-in programs— not on by default like T-Mobile’s.

Fortunately, it’s relatively easy to opt-out of T-Mobile’s targeted ads. Simply go to T-Mobile.com, click on Account > Profiles > Privacy and Notifications > Advertising & Analytics and toggle “Use my data to make ads more relevant to me” to “Off.”

While it may be easy to turn the feature off, that doesn’t change the fact it should never have been an opt-out proposition. It’s one thing for free services, such as Facebook and Google, to make money off of targeted ads that use personal data and infringe on privacy, but it’s quite another for a paid service to presume to do the same. For a company that prides itself on protecting the consumer to do so…well, that’s just unconscionable.

T-Mobile’s actions in this instance are more “Carrier” than the two wireless carriers it constantly mocks.