Personal data harvesting for contextual ads and content should be a beautiful thing. Companies monitor what you do, where you go, who you interact with and what your interests are. They do it privately and securely, and it's all automated so that no human being actually learns anything about you. And then the online world becomes customized, just for you. The ads are always the things you want to buy. The services are just what you're looking for. The content is exactly the stuff you enjoy.
It doesn't always work that way, but that's how it's supposed to work.
What's wrong with the public anxiety about this scenario People are mostly concerned about the privacy violation. But it could be argued that there is no such violation, in most cases. It's really a philosophical question as to whether your privacy has been violated if no human being sees your data.
The real problem with this scenario is that is we're paying for contextual ads and content with our personal data, but we're not getting what we pay for.
That's true of most supposedly contextual advertising. And it's true of most personalized content.