In that post I mentioned how Firefox had started the work, pulled it, and then brought it back. Well now it's official. You can read up on how it works at the Mozilla Wiki, where they were kind enough to put together a DoNotTrack FAQ. The FAQ helps readers understand that this is not the solution that will ultimately be implemented, since it relies on an HTTP header.
Google is relying on a cookie-based approach via a browser add-on. The only real difference from the voluntary Network Advertising Initiative that allows users to opt-out, which relies on cookies, is that the Chrome add-on won't blow away those cookies when a user clears all other cookies on his/her browser. You can read up on the confusingly-named Keep My Opt-Outs on one of the Google blogs (there are so darn many).
I suggest that if you plan on using these new features, which are not enabled by default and require some level of configuration to be useful, that you take a few minutes to read up on them:
- Mozilla, Google take different approaches to ad tracking opt-out at ars technica.
- Mozilla & Google Announce Browser "Do Not Track" Features at Mashable.
- Firefox and Chrome Add "Do Not Track" Tools To Their Browsers at ReadWriteWeb.
- Web Tool On Firefox To Deter Tracking at Wall Street Journal.
- Protecting Consumer Privacy in an Era of Rapid Change, preliminary FTC staff report (PDF).
- Self-Regulatory Program for Online Behavioral Advertising
- Network Advertising Initiative
- chrome-opt-out-extension at Google code blog.
- Keep My Opt-Outs from the Chrome web store.
- More Choice and Control Over Online Tracking from the personal blog of the Global Privacy and Public Policy Leader at Mozilla.
- Thoughts on Do-Not-Track from Michael Hanson, Mozilla Labs.
- Big browsers hop aboard the 'Do Not Track' train at New Scientist, Jan. 27, 2011.