Cell carrier privacy settings to change now

Your carrier can use your web history, app use and sometimes even location to help advertisers target you

(The Washington Post illustration; iStock; Verizon; AT&T; T-Mobile)

Apps and devices aren’t the only tech in your life due for a privacy check. Your cellphone carrier is likely peeking into your personal information, too.

In response to a reader question in April, we examined the privacy policies of the three major carriers in the United States — AT&T, T-Mobile and Verizon — and found that all of them can use data such as your web history for targeted advertising.

That in itself was surprising, but worse was that I had no memory of saying “yes” to my carrier’s ad program, and I wasn’t alone. There’s a good chance you were automatically opted in or failed to un-check a consent box during sign-up.

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These programs work by collecting data about you — which in some cases includes your precise location, call history, web history and installed apps — and then targeting you with ads or charging advertisers for access to inferences about you.

If you would rather not contribute to your cell carrier’s on-the-side ad business, you can opt out. (Your carrier can still collect data from you to market its own products and services.)

For AT and T

If you’re an AT&T customer, you were automatically opted into its “relevant advertising” selection, which lets the company use your browsing history and videos you watch to put you into “interest categories” it can share with advertisers, a spokesman said.

If you ever clicked “yes” to something called “enhanced relevant advertising,” AT&T can also use your location and call history. It says it can combine data with your Android or iOS IDs (strings of numbers tied to your device), which could help advertisers better track you across different apps. It also says it can combine its data with data from third parties — including your credit information — to get an even clearer picture of you and your behavior. Yikes.

Mercifully, AT&T gave us a direct link to its opt-out page right here.

For T-Mobile

T-Mobile’s ad program uses data including app use to group customers into “personas.” Then, third-party advertisers pay for access to that information.

Unlike AT&T and Verizon, T-Mobile doesn’t appear to use precise location to target advertisements.

To opt out of T-Mobile’s ad business, open the app, go to “More” on the bottom right, then “Advertising & Analytics,” then “Use My Data To Make Ads More Relevant To Me.” Turn the toggle off so that it turns gray. On the website, try going to “My Account,” then “Profile.” Click “Privacy and Notifications,” then “Advertising and Analytics,” then “Use My Data To Make Ads More Relevant To Me.” Turn the toggle off.

For Verizon

Verizon customers are automatically opted into the company’s “custom experience” program, so their browsing and app use can be used for ads, according to Verizon’s website. If you consented to “custom experience plus,” your precise location and call history come into play.

The company’s website says it uses this information to group you into personas. A spokeswoman declined to say whether those personas or other inferences ever get shared with third parties.

To opt out, sign into your account on the My Verizon app, go to “Edit Profile and Settings,” scroll down to “Preferences” and choose “Manage Privacy Settings.” For each of your phone lines, turn the toggles for “custom experience” and “custom experience plus” into the “off” position. While you’re there, turn off “customer proprietary network info,” which includes your call history.