I don't see how aggregate data is 'about you' in a way that impacts privacy, unless they aggregate it from just a few users.
From one of your linked comments:
> Abstracted profiling still works, and digs deeper than you might suspect (I recall the netflix data that could predict interests across different categories, like people watching House of Cards also liking It's Always Sunny in Philadelphia).
Abstracted profiling (if we're talking about the same thing) predicts things about the user - otherwise it wouldn't be valuable - but the question is whether it identifies the user.
> It's also just part of the long slow, death by one thousand cuts transformation into a company that doesn't have categorical commitments to privacy
They've been doing privacy-preserving ads for - a decade? It's not part of a transformation. The claim that Mozilla "doesn't have categorical commitments to privacy" would need to be stablished, unless 'categorial' means 'absolutely perfect in every way'.
The notion of 'privacy preserving' ads, or that the data they are selling is not in some sense 'about you.'
I talk about this in a couple of other comments.
https://news.ycombinator.com/context?id=43212048
https://news.ycombinator.com/context?id=43212010