[_delirium]

I think people don't notice it until it's all presented back to them in some manner like this.

People might also have an unreasonable expectation that there's some law against misusing their data. Partly, it's because that is true in some areas, e.g. the phone company can't run speech-to-text on all your conversations and sell histograms of your word usage, so people might assume Facebook can't either.