An online advertising clearinghouse relied on by Google, Yahoo and Facebook is using controversial cookies that come back from the dead to track the web surfing of Verizon customers.
The company, called Turn, is taking advantage of a hidden undeletable number that Verizon uses to monitor customers' habits on their smartphones and tablets.
Turn uses the Verizon number to respawn tracking cookies that users have deleted.
"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.
Turn's zombie cookie comes amid a controversy about a new form of tracking the telecom industry has deployed to shadow mobile phone users. Last year, Verizon and AT&T users noticed their carriers were inserting a tracking number into all the Web traffic that transmits from a users' phone – even if the user has tried to opt out.
Users complained that the tracking number could be used by any website they visited from their phone to build a dossier about their behavior – what sites they went to, what apps they used.
In November, AT&T stopped using the number. But Verizon did not, instead assuring users on its website that "it is unlikely that sites and ad entities will attempt to build customer profiles" using its identifiers.
It works like this: When a user visits a website that contains Turn tracking code, the company holds an auction within milliseconds for advertisers to target that user. The highest bidder's ad instantly appears on the user's screen as the web page loads. Turn says it receives 2 million requests for online advertising placements per second.
For its auctions to work, Turn needs to identify web users by cookies, which are small text files that are stored on their computers. The cookies allow Turn to identify a user's web browsing habits, such as an interest in sports or shopping, which it uses to lure advertisers to the auction.
Some users try to block such tracking by turning off or deleting cookies. But Turn says that when users clear their cookies, it does not consider that a signal that users want to opt out from being tracked.
"There are definitely people who feel that if they clear their cookies, they won't be tracked, and that is not strictly accurate," said Joshua Koran, senior vice president of product management at Turn.
Turn executives said the only way users can opt out is to install a Turn opt-out cookie on their machine. That cookie is not designed to prevent Turn from collecting data about a user - only to prevent Turn from showing targeted ads to that user.
Does Your Phone Company Track You?
Click from your smartphone or tablet (with Wi-Fi turned off) to see if your telecom provider is adding a tracking number. We don't save any information.
here
Zombie Cookie: The Tracking Cookie That You Can’t Kill - ProPublica
The company, called Turn, is taking advantage of a hidden undeletable number that Verizon uses to monitor customers' habits on their smartphones and tablets.
Turn uses the Verizon number to respawn tracking cookies that users have deleted.
"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.
Turn's zombie cookie comes amid a controversy about a new form of tracking the telecom industry has deployed to shadow mobile phone users. Last year, Verizon and AT&T users noticed their carriers were inserting a tracking number into all the Web traffic that transmits from a users' phone – even if the user has tried to opt out.
Users complained that the tracking number could be used by any website they visited from their phone to build a dossier about their behavior – what sites they went to, what apps they used.
In November, AT&T stopped using the number. But Verizon did not, instead assuring users on its website that "it is unlikely that sites and ad entities will attempt to build customer profiles" using its identifiers.
It works like this: When a user visits a website that contains Turn tracking code, the company holds an auction within milliseconds for advertisers to target that user. The highest bidder's ad instantly appears on the user's screen as the web page loads. Turn says it receives 2 million requests for online advertising placements per second.
For its auctions to work, Turn needs to identify web users by cookies, which are small text files that are stored on their computers. The cookies allow Turn to identify a user's web browsing habits, such as an interest in sports or shopping, which it uses to lure advertisers to the auction.
Some users try to block such tracking by turning off or deleting cookies. But Turn says that when users clear their cookies, it does not consider that a signal that users want to opt out from being tracked.
"There are definitely people who feel that if they clear their cookies, they won't be tracked, and that is not strictly accurate," said Joshua Koran, senior vice president of product management at Turn.
Turn executives said the only way users can opt out is to install a Turn opt-out cookie on their machine. That cookie is not designed to prevent Turn from collecting data about a user - only to prevent Turn from showing targeted ads to that user.
Does Your Phone Company Track You?
Click from your smartphone or tablet (with Wi-Fi turned off) to see if your telecom provider is adding a tracking number. We don't save any information.
here
Zombie Cookie: The Tracking Cookie That You Can’t Kill - ProPublica
