In practical terms, the revamp means that Verizon will no longer insert the tracking headers whenever customers' visit unencrypted sites, according to Nate Cardozo, an attorney with the digital rights group Electronic Frontier Foundation. Instead, the headers will be used on sites affiliated with AOL's ad network -- which reaches around 40% of the Web.
From a privacy viewpoint, that narrowing of the program marks a "significant positive development," Cardozo says.
But he adds that the EFF wants Verizon to still stop tracking users without their explicit permission. "From our perspective, Verizon should kill the program," says Cardozo. "Verizon is tampering with its customers' traffic without effective notice and choice."