I agree - I never post private data to Facebook. But now it doesn't matter if I post private data to Facebook or not. They can start hoarding data from my visits to yelp or pandora or whatever else in the future if I merely forgot to log out of Facebook before going to yelp. And yes, I can change my privacy settings to make them not, but today, I missed the tiny blue banner in Yelp that gave me the option to opt-out, and then it was kind of a pain to figure out how to opt out of whatever I just accidentally opted into. It's turning into a real hassle for me to keep facebook from creeping into the non-facebook parts of my internet experience.