T-Mobile is starting a new program that collects and shares data with advertisers in order to show you ads more relevant to your interests. Customers will be included by default, but will be allowed to opt out. The carrier announced the change in a privacy policy update last month, and it was spotted by the Wall Street Journal on Tuesday. 

The new policy will affect both T-Mobile and Sprint customers, since the companies merged last year, and will allow the carrier to share info like your browsing data and the apps you use. The policy will go into effect on April 26. The company clarified that the info it collects won't be tied to your name, but it will link to a unique mobile advertising identifier.