The nation’s largest wireless provider has come under fire over its plan to launch a new marketing initiative that critics say is invasive of users’ privacy. Starting this week, Verizon Wireless (VZ) will begin sending select customers advertisements based on location data, web browsing habits and mobile application usage, as well as other information such as customer demographics and interest data. The program, known as Verizon Selects, will then target customers with various services, coupons and promotions through online or mobile advertisements, email, text message and postal mail based on the collected information. Privacy advocates have voiced their concerns with the program, however Verizon maintains that all information collected is anonymous and the program itself will be opt-in only.

“We are asking customers to opt-in to Verizon Selects because of the types of information being used and because the capabilities provided to third-party marketers gives them the ability to reach customers directly,” the company wrote on its website. “It’s important to remember that Verizon DOES NOT share information that identifies customers personally outside of Verizon.”