Mozilla offers do-not-track tool to thwart ads

Firefox developer has offered a proposal to let browsers tell Web sites when people don't want behaviorally targeted advertising. Will advertisers play ball?

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Stephen Shankland
3 min read
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Mozilla, acting on a U.S. Federal Trade Commission proposal, has offered a detailed mechanism by which Firefox and other Web browsers could prevent Web pages from tracking people's online behavior for advertising purposes.

With Mozilla's do-not-track technology, network data packets from the browser would signal to a Web site that a person doesn't wished to be tracked. Then comes the tricky part: getting Web site operators to cooperate.

Alex Fowler, Mozilla's global privacy and public policy leader, said that with the mechanism, the browser would alert a Web site during basic communications that use the Web's Hypertext Transfer Protocol (HTTP). He also acknowledged that getting Web sites to cooperate is a crucial difficulty in getting the system to work:

As the first of many steps, we are proposing a feature that allows users to set a browser preference that will broadcast their desire to opt-out of third party, advertising-based tracking by transmitting a Do Not Track HTTP header with every click or page view in Firefox. When the feature is enabled and users turn it on, Web sites will be told by Firefox that a user would like to opt-out of OBA [online behavioral advertising]. We believe the header-based approach has the potential to be better for the Web in the long run because it is a clearer and more universal opt-out mechanism than cookies or blacklists...

The advantages to the header technique are that it is less complex and simple to locate and use, it is more persistent than cookie-based solutions, and it doesn't rely on user's finding and loading lists of ad networks and advertisers to work...

The challenge with adding this to the header is that it requires both browsers and sites to implement it to be fully effective. Mozilla recognizes the chicken and egg problem and we are taking the step of proposing that this feature be considered for upcoming releases of Firefox.

Mozilla's explanation of its proposed do-not-track technique for letting people opt out of behaviorally targeted advertising.
Mozilla's explanation of its proposed do-not-track technique for letting people opt out of behaviorally targeted advertising. Mozilla

Mozilla has long had privacy as part of its mission to empower users of the Internet. In practice, privacy remains a broad, thorny problem, however; what one person sees as corporate intrusiveness another can see as a way to offer genuinely relevant ads.

Mozilla doesn't appear to be acting alone. Today, "Google is expected to announced a privacy tool called 'Keep My Opt-Outs' that enables users to permanently opt out of ad -targeting from dozens of companies," The Wall Street Journal reported yesterday, citing an unnamed source.

The FTC proposed a Do Not Track mechanism last year (click for PDF).

"While some industry members have taken positive steps toward improving consumer control, there are several concerns about existing consumer choice mechanisms," the FTC said. Among them, "industry efforts to implement choice on a widespread basis have fallen short," consumers aren't generally aware of the technology when it's available, and it can be hard to use.

"Given these limitations, [FTC] staff supports a more uniform and comprehensive consumer choice mechanism for online behavioral advertising, sometimes referred to as 'Do Not Track,' the report said. "Such a universal mechanism could be accomplished by legislation or potentially through robust, enforceable self-regulation."

For details on Mozilla's proposal, check posts by Sid Stamm and Mike Hanson. Also available is Mozilla's do not track FAQ.