Online advertisers go on tracking you even if you opt-out of tracking

A new study reveals that some online advertising networks continue tracking Web Users even though the latter use opt-out requests and the networks promised to take into account these requests.

Stanford University's Center for Internet Society reports that 8 members of the Network Advertising Initiative, a cooperative of online marketing and analytics companies, promise to stop tracking people who use the NAI's service to opt out of targeted advertising, but continue to leave tracking cookies on those people's computers.

The survey suggested one US lawmaker to urge Congress to adopt a new legislation on privacy matters and ask one privacy group to call for an investigation by the U.S. Federal Trade Commission.

Under the terms of NAI’s opt-out rules there is no requirement for members to stop tracking people, just to stop delivering targeted advertising, noted Jonathan Mayer, lead developer of the Stanford center's new Web measurement tool used to test the opt-out mechanism. The study revealed that 33 of 64 NAI members left cookies in place after a Web user opted out of targeted ads.

The Stanford study puts the distinction between targeted advertising and online tracking, said Charles Curran, NAI's executive director. While there's a policy debate in Washington, D.C., about do-not-track mechanisms, there's no consensus on what do-not-track means, he said in a blog post.