You love playing those games on facebook? WSJ reports that many of the popular games developed by Zyang, the mega Facebook games developer have been sharing user information with third parties. These information include user ID, which advertisers and other tracking firms can use to look up user's names and other info on the social network. Although sharing user info goes against Facebook's own rule these apps have been reported to have shared user info. 

You love those virtual farms and farming on the internet, think about it.