Before, you should consider everything you wrote in Facebook as public. Now with Open Graph, the new application Mark Zuckerberg presented, everything YOU DO in Facebook will be public too.
First, Facebook observed that asking people to manually Like, Share, or Comment on content requires an extra step that actually inhibits sharing and interaction. Rather than introduce changes to the buttons, it will simply change the technical framework for apps within Facebook so that rather than requiring you to click to share, comment or express sentiment, the app automatically broadcasts a status update for you. For example, with the new Facebook and Spotify integration, simply listening to music automagically updates my News Feed (eventually my timeline). Depending on how much interaction it triggers, that activity may also show up in your News Feed.
So now you know. As your Internet Reputation is becoming increasingly important, be aware of the capabilities of the new tools!
Now, like in Quantum Physics, knowing that you are being observed may change your behaviour :-) Unluckily it also increases the stress of the person being watched.
Check the full article: Whoops, I didn’t mean for you to read this