When Verizon first announced its plans to acquire AOL back in May, jokes abounded. The name “AOL” still conjures the sound of modems screeching and a friendly digital voice announcing haltingly, “You’ve got mail!” It does not, on the other hand, immediately inspire one to think of a $4 billion media and data empire. But the latter is exactly what it is — and in conjunction with Verizon’s more pernicious tools, it may be about to get a whole lot bigger.

The merger raised red flags for privacy advocates when it was announced, and those concerns are proving to have been right on the nose, ProPublica reports. It comes down to tracking: who’s doing it, what they’re learning, and where the data goes.

Remember those troublesome tracking “supercookies” Verizon was putting on users’ phones? Here’s a refresher: Verizon appends a little header that you can’t see to all web traffic coming out of your phone. The tracker, called a UIDH (unique ID header) is consistent and permanent. Unlike regular trackers, clearing out your browser cookies and checking your privacy settings doesn’t do anything about these. And they build a comprehensive, unique, entirely trackable history of basically everything you’ve ever Googled or visited on your phone.

After media reports triggered a hue and cry, Verizon has finally been permitting users to opt out since April. Those supercookies, though, are still present for anyone who hasn’t specifically disabled them… and now, thanks to the AOL acquisition, they serve an internal purpose for Verizon.

The other half of the equation is AOL’s advertising network, which is substantial. It’s not quite a Google or a Facebook, but it’s still a huge player in the space — and with the new information from Verizon added to it, poised to become larger still.

Verizon will have all of that tracking data from your phone. It will be anonymized, for what that’s worth, and then combined with AOL’s ad network data. The combination works out in Verizon and AOL’s favor, by allowing the company to serve you more ads, in more spaces, that are theoretically better targeted to your individual interests and, therefore, more likely to make you buy stuff.

Privacy advocates have pointed out that not only is the data potentially intrusive, but also unencrypted, and easily intercepted. Karen Zacharia, chief privacy officer at Verizon, told ProPublica, “I think in some ways it’s more privacy protective” than working with third-party ad networks would be, “because it’s all within one company.”

Verizon’s Zombie Cookie Gets New Life [Pro Publica]

Want more consumer news? Visit our parent organization, Consumer Reports, for the latest on scams, recalls, and other consumer issues.