The search engine reckons that because Microsoft's browser has DNT turned on automatically it "doesn't express user intent" so it's just going to ignore it altogether.
Of course, it's in Yahoo's interest to ignore DNT – the search engine uses tailored results to serve up more relevant, higher-returning adverts.
"Our users have come to expect a personalised Yahoo experience tailor-made for their lives," the company wrote in a statement.
"We fundamentally believe that the online experience is better when it is personalised."
DNT is not so much a rule as a guideline; when you turn it on in your browser settings (on IE, Safari or Firefox, at least – Chrome doesn't support it yet), it tells advertisers that you don't want to have your movements across the web monitored.
This puts the kibosh on search engine's plans to personalise every result they serve you because you've told them that you don't want them to use the fact that you visited Wardrobes R Us in order to return wardrobe-relevant ads or search results at a later date.
However, not all websites support the movement - Twitter is one of DNT's most high-profile supporters, but some major sites like Facebook still choose to ignore it.
Microsoft made the controversial decision to make DNT the default setting in IE10, which means users who don't mind advertisers and other third-parties tracking their movements online will have to physically turn it off.
However, not all advertisers abide by DNT which means you're sending a message about what privacy you'd like to have, rather than actually keeping any data private.
To Yahoo's credit, it claims that this isn't the end of DNT for Yahoo users, concluding its blog post on the matter saying that it is still "committed to working with the World Wide Web Consortium to reach a DNT standard" as long as that standard suits both users and its own search engine needs.