From Media Post
Microsoft’s controversial decision to turn on a do-not-track header by default in its newest browser is drawing heated criticism from ad industry representatives, who criticize the software giant for taking a position contrary to self-regulatory groups.
A browser-based do-not-track header sends a request to Web sites, but doesn’t block cookies or prevent tracking users in order to send them ads based on their online activity.
MediaPost Publications DAA: Ad Industry Might Ignore IE10 Do-Not-Track Requests 06/04/2012.