Ars Technica reports on a new study from Stanford’s Center for Internet & Society concerning Do Not Track technology. (Do Not Track proposals would allow consumers to restrict the data gathered by Web sites and marketers on the consumers’ online browsing or purchases.) Here’s the blurb from CIS: “One of our chief applications is a system for automated enforcement of Do Not Track by detecting the myriad forms of third-party tracking, including cookies, HTML5 storage, fingerprinting, and much more. […] Please bear in mind that these are preliminary findings from experimental software.” Here’s what Ars has to say:
The Network Advertising Initiative (NAI) is one of several self-regulating groups aimed at adopting voluntary codes of conduct when it comes to advertising to users online. Late last year, those groups (including the NAI) announced that they would begin pushing the Advertising Option Icon, an icon that is meant to let users know which sites are participating in behavioral tracking. Users would then be able to easily opt out of any behaviorally targeted advertising if they so choose. Collectively, the groups represent some 5,000 other companies that advertise online, though use of the icon itself is voluntary as long as they offer the opt-out functionality.
But how many companies are actually respecting those rules? Stanford’s Center for Internet & Society recently examined the tracking behavior of 64 of 75 of NAI’s member companies when users turn on the Do Not Track settings or opt out of behavioral ad tracking. Of the 64, the CIS said that 33 companies left their tracking cookies in place after the user opted out. This in itself sounds surprising, but it’s not—as part of their agreement with NAI, companies only have to agree to stop offering behaviorally targeted ads to users when users want to opt out. They can continue to keep cookies on your machine, as long as those cookies aren’t being used to create specially targeted ads. […]
That leaves us with the eight companies dwelling in the hall of shame: 24/7 Real Media, Adconion, AudienceScience, Netmining, Undertone, Vibrant Media, Wall Street On Demand, and TARGUSinfo AdAdvisor. These guys all specify in their privacy policies that users can opt out of behavioral tracking and advertising, but the CIS researchers found that they all kept some form of unique user information around on the user’s computer even after opting out. Most of them removed certain pieces of information while keeping other items, but one (Vibrant Media) simply kept on tracking as if the user had never opted out in the first place.
Read the full article for more on the study and also some responses from the companies mentioned.