According to Microsoft VP Dean Hachamovitch, after the Cookies hit Safari the Internet Explorer team discovered that the Google was employing similar methods to get around default Privacy settings in IE and to track the browsing behavior of the users with the Cookies.
The Microsoft Team has found that Google bypasses the P3P Privacy Features in IE to track users. Microsoft Says that Google is Breaking the Rules. More about this is provided here.
In a statement, Google says that :
The Journal mischaracterizes what happened and why. We used known Safari functionality to provide features that signed-in Google users had enabled. It is important to stress that these advertising cookies don't collect Personal Information.
Basically, Google wrongfully bypassed the protection and enable its cookies to be allowed rather than be blocked. Thus allowing to track the browsing habits of Safari & IE users.
In the Mean time Microsoft have created a Tracking Protection list to protect the IE users from Google which could be found in the IE Blog
