Do Not Track is a technology that enables users to opt out of third-party web tracking, including behavioral advertising. At present a user cannot opt out of many of the hundreds of tracking services and advertising networks; those that do allow opting out each require setting (and not deleting!) an opt-out cookie. Much like the popular Do Not Call registry, Do Not Track provides users with a single, persistent setting to opt out of web tracking.
According to the WSJ, the tool is included within the latest test release of Lion, a version of Apple's Mac OS X operating system that is currently available only to developers. The final version of the operating system is scheduled to be released to the public this summer. Mentions of the do-not-track feature in Apple's Safari browser began to appear recently in online discussion forums and on Twitter.
Unfortunately, major online-advertising networks have not yet agreed on how to honor the system.
Read More [via MacStories]