On the other hand, privacy isn't a tangible phenomenon; it's a normative judgment about what should and shouldn't be shared. As big data grows increasingly common, our sense of what is and isn't private will surely change. For instance, I'd be outraged if someone posted my phone number on the Internet without my consent, but to this day, we publish phone books with the name, phone number, and address of everyone in each community.

For better or worse, we'll probably grow less and less distressed at the prospect of our tastes and preferences being used to drive advertising and other decisions. So long as those decisions are fundamentally benign, anyway: we can probably agree that American Express lowering someone's credit limit on the basis of big data harms them unfairly, whether it's a breach of privacy or not.

-- SamuelRoth - 17 Sep 2014