This Advertiser Can Track You Anywhere on the Internet

If you're a Verizon customer, congratulations! It's really, really easy for advertisers to track your every move online, thanks to a so-called 'zombie cookie' that is impossible to delete.

​According to ProPublica, an online advertising company called ​Turn has developed a tracking cookie that, even after deleted from your computer or device, can be re-installed without your consent. And it's all Verizon's fault.

Last fall, ​it was discovered that Verizon and AT&T had both been inserting hidden, unique tracking codes into its users' internet activity (AT&T ceased the practice in November, however). In other words, if you were to visit a site using Verizon's networks, your connection to our servers would come with a unique ID that its administrators could use to track other sites you've visited and apps you've used. Most don't.

But a company called Turn is. According to ProPublica, they've been using this unique ID to keep track of users, and ensure that the company's tracking cookies can't be removed from a users' device.

"We are trying to use the most persistent identifier that we can in order to do what we do," Max Ochoa, Turn's chief privacy officer, told ProPublica reporters Julia Angwin and Mike Tigas—which isn't scary at all.

The reason these IDs are useful to advertisers and wireless carriers is obvious: because they are more persistent than traditional cookies, users can be tracked more readily, and be delivered more targeted, higher-quality ads. When you visit a site with a Turn tracking code, advertisers can bid on the chance to display an ad on your device. In order for Turn to keep track of who its visitors are—not to mention, their interests and other demographic information valuable to advertisers—a small cookie is installed.​

Normally, you should be able to delete such a cookie, preventing advertisers from being able to track your browsing or app activity from one session to the next. But because all Verizon internet activity has a unique tracking code embedded in each connection you make to a remote server, Turn simply needs to look for Verizon's tracking code when a user connects to a Turn-enabled site. Turn can use this code to determine your identity, and re-install the company's tracking cooke in the event it's been deleted.

Turn's senior vice president of product management Joshua Koran says that the company doesn't consider the removal of Turn's cookie an indication that a user may want to opt-out from being tracked. And while users can apparently opt-out from receiving Turn's targeted advertising—by installing yet another cookie—they can't actually opt-out from being tracked.

Your only solution, unfortunately, is is to toss your Verizon phone out the window. All wireless carriers suck in some way, but at lease there are some that will respect your desire to not be tracked.