I waffled between this going here and in window's security and I settled for here, since it's more privacy than security (though to many myself included the are relatively tied to on-another).
According to Qualys Yahoo has looked at the Do Not track mechanics of IE10 and decided that they would not honor User's Wishes
TOP VULNERABILITY THIS WEEK
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Title: Yahoo, Microsoft spar over default Do Not Track
Description: In an effort to boost privacy on the web, Microsoft has
enabled Do Not Track features by default in Internet Explorer 10, the
browser it recently released as part of Windows 8. Citing a need to
customize the user experience and a lack of standardization, however,
Yahoo - still one of the largest properties on the Web, despite recently
declining market share - announced this week that it will not honor that
setting. Privacy advocates are abuzz discussing the implications of the
decision, which is certain to spark an impassioned discussion of the
balance between privacy and user experience on the modern Internet.