Verizon has been spotted this past January for loading “supercookie” with every smartphone. Like more traditional Internet cookies, supercookies track users’ online behavior to serve them up targeted advertisements, but unlike regular cookies, supercookies are impossible for users to delete.

Mobile devices on the carrier’s network include a Unique Identifier Header, or UIDH. This is a unique tracking code that authorizes the carrier to monitor your online activities and analyze your interests. This data is then used for targeted advertisements through the company’s Relevant Mobile Advertising (RMA) and Verizon Selects program.

As mentioned on Verizon’s website, “for RMA, Verizon creates groups of customers for advertisers to reach based on demographic and interest-based information provided to us by other companies.We then relay anonymous information about these groups to our ad partners to enable them to serve relevant ads. If a customer has opted in to Verizon Selects, we will create groups of customers using additional information we have about customers’ location, Web browsing and app usage.”

There was previously no way to delete the so-called “supercookie” tracking code from your device. Verizon customers can now choose to opt-out of a controversial advertising program that used.

As of Tuesday evening, the New York Times reports, Verizon’s systems have been changed to stop inserting the tracker for customers who opt out of the program.

You can visit this page on Verizon’s website. Simply log in and follow the on-screen instructions to opt out of RMA. A similar opt-out procedure is also available in the My Verizon mobile app.It can also be done by calling 1-866-211-0874, or by heading to the privacy settings on Verizon’s website or in the My Verizon mobile app.

A representative for Verizon said in a statement, “As the mobile advertising ecosystem evolves, and our advertising business grows, delivering solutions with best-in-class privacy protection remains our focus.”