The latest action on the browser wars battlefield is a dual of opt-out skills. Yesterday, both Mozilla and Google announced the inclusion of tools in their respective browsers that make it easier for users to withdraw from behavioral tracking. 

Mozilla's Method: Do-Not-Track!

When a computer sends or receives information over the Web, the request begins with a header, which includes information like what browser a consumer is using, what language their computer is set to, etc. Mozilla's proposal for opting-out basically inserts a bit of information into each header that says, Hey tracking tools, this information is off limits.   

Alex Fowler, global privacy and public policy leader at Mozilla is a bit more eloquent in his explanation: “When the feature is enabled and users turn it on, websites will be told by Firefox that a user would like to opt out of OBA. 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 "clearer" and "more universal" claim comes from the fact that a header-based opt-out system puts out a signal with every online communication indicating a user's preference not to be tracked. This places the responsibility to comply with Do Not Track mechanisms on tracking companies, rather than on the user to discover every type of tool as they're improved and released. Further, consumers won't need to regularly update software, and they can clear cookies without disrupting the system. 

The announcement makes Firefox the first Web browser to heed the Federal Trade Commission's call for the development of a do-not-track system, and will reportedly be included in the next release of the browser, Firefox 4.1. 

Google's Method: Keep Your Opt-Outs

Meanwhile,  Google has released a new extension for Google Chrome called Keep My Opt-Outs. Big G's approach is an add-on that ties into the browser's internal cookie APIs in order to make sure that the the proper opt-out setting is configured for each advertising network. In order to accomplish this, the add-on bundles a JSON-based registry of the major advertising network domains and the required value in the cookie for each one.

"Google's approach is effective and pragmatic because it simply wraps the existing cookie-based opt-out mechanisms that are offered by the advertising companies," explained Ryan Paul of ars technica. "The manner in which it attempts to intercept and rewrite cookies, however, poses some minor challenges and is arguably a suboptimal technical solution."

Who's Winning? 

Survey says Mozilla's header approach is comparatively simpler and would perhaps be more effective in the long run than Google's add-on. For the tool to even work, however, tracking companies would need to agree to not monitor users who enable the feature. As of now, not one company has publicly agreed to participate. 

On that note, it's important to keep in mind that neither Google's add-on nor Mozilla's proposed header will actually block tracking. Both solutions rely on the advertising industry to comply with user preferences.