A great overview of what you should be worried about on the web when it comes to your data and what folks can do with it. If you really want to dive in on this, the linked article from the EFF really expands on the ideas. As the author states above, I’m also not opposed to advertising in principle. What I’m opposed to is the massive amount of personalized data companies gather about me to deliver mediocre ads that are not any better than those you might get in a non-targeted way.