I think what he's saying is that they do the inferences from localhost, more or less (see e.g. https://www.microsoft.com/en-us/research/publication/serving-ads-

I think what he's saying is that they do the inferences from localhost, more or less (see e.g. https://www.microsoft.com/en-us/research/publication/serving-ads-from-localhost-for-performance-privacy-and-profit/ https://www.microsoft.com/en-us/research/publication/serving...) There are a number of proposed systems under the rubric of "privacy preserving advertising systems" and they are very different than what ad-revenue driven companies are doing today and similar to what he is proposing above.