Advertising is Facebook's reason for being, but this story is about people over-sharing with other people (mediated through APIs). Advertising appears irrelevan

Advertising is Facebook's reason for being, but this story is about people over-sharing with other people (mediated through APIs). Advertising appears irrelevant, except insofar as it's Facebook's reason for being. If Facebook did exactly as you suggest and walled off advertisers from all but aggregate user detail, it wouldn't have affected this app, or anyone using similar techniques.