Just to be clear: Anything done on the grid is public forever

http://techcrunch.com/2011/07/27/the-seemingly-unanswerable-question-can-the-government-use-location-data-to-hunt-us-down/?utm_source=feedburner&utm_medium=feed&utm_campaign=Feed%3A+Techcrunch+%28TechCrunch%29

If your somewhere you don't want the world to know about, take your battery out of you phone long before you get there.  Don't email things you don't want in the open.  Assume every credit card purchase can be used against you.  Buy too much ice cream and watch your health insurance premiums rise.  Imagine a two price system: untrackable cash and trackable credit where the cash price is higher because the tracking information from credit purchases is resold to health insurance companies (saturated and trans fats), car insurance companies (alcohol), advertisers (everything).  To some extent we already have this with cash back credit cards, but how high might the % climb.  I get 2%.  You?