The conversation around 'Do Not Track' has been brought in to the spotlight after Microsoft announced that by default,
IE10 will enable DNT when browsing the web. To make a long argument short, advertisers were pissed off about this because they want to be able to track you so that they can deliver targeted advertisements but of course, with DNT enabled by default, this could put a dent in their CPM metrics.
What you have in one corner is the corporations and in the other corner privacy advocates and Microsoft has just penned up a post re-affirming their stance to maintain default DNT on IE and will continue to fight for this as the standard is deliberated with the W3C.