In all the comments here, I can't find anybody who thinks that Yahoo is doing the right thing here. Well, I do. I think what Yahoo is doing is the right thing for them, for their users, and for the web.<p>If the web is going to be ad supported, then its going to have to be targeted advertising or its going to be both shit and annoying. Remember "punch the monkey", or ads that took over the entire screen? Now, through tracking, we are able to get really really good ads - things you might even be interested to see and buy.<p>If DNT was supported by everybody and on by default, that's the end of online advertising in its current form. So we can choose from the following options: ignore DNT, ignore DNT for IE10, or go back to non-targeted advertising.<p>Let's assume the last of those, which leads us to the following options: revert to shit ads, make users pay for content directly, or pack up your content-producing company and go home. None of these are best for the users or the web.<p>The DNT founders know this - that's why it was default null in the spec and in Firefox. IE10 is doing this deliberately even though they know it can't work, and there are choices here: they are trying to improve the world but are incredibly wonderfully naive, they want to undermine Google, or they want to undermine DNT. I'd love to believe its the first, but no-one has ever claimed that about MS.