AT&T Mobility said Friday it's no longer adding Internet tracking codes to data transmitted from its users' smartphones. Seperately, the company will stop investing in high-speed Internet connections until the FCC sorts out the new "net neutrality" rules. Until now, cellphones operating under AT&T's network passed along "cookies" or small strings of characters to websites that a consumer visited with his mobile device. The information could be used to track subscribers across the Internet and thus, advertisers could take advantage of users' identities and serve them with ads related to their browsing habits.

AT&T said Friday its tracker was part of a testing project that's been phased off of its network.

Verizon Wireless, America's largest mobile firm, is also using such techniques but not for its business and government customers. Earlier this month, investigative website ProPublica discovered that Twitter's advertising arm was using Verizon's tracking codes.

In related news, AT&T has decided to stop investing in high-speed Internet connections in 100 cities until the U.S. Federal Communications Commission (FCC) finalize the so-called net neutrality rules. The announcement followed the recent call by President Barack for stricter rules governing the way Internet service providers manage their traffic.

The U.S. Federal Communications Commission on Friday asked AT&T to provide specifics of its decision. In a letter, FCC asked the wireless carrier to detail its plans to limit fiber deployment and to turn over all documents on the decision by Nov. 21.

The FCC is reviewing AT&T's proposed $48.5 billion bid to buy satellite operator DirecTV. As part of the merger proposal, AT&T agreed to provide high-speed fiber Internet to 2 million homes if the deal is approved.