Are you make friends on facebook, and what functioning of this friend, are you utilize the friendship on facebook. Actually not all friend of you on facebook really want make friend with you, but almost of them just make friend collection on their account. This because like on facebook mention box also write "What in your oppinion?" it's mean you must write anything on your oppinion but almost all of the oppinion have nothing mean to others. Facebook want that you always update your status and for this action facebook will always changes and always crawl by search engine because the data always changes inside.
Search engine just keep all of information come to them and can't read the content inside the status even it just bulshit. But facebook have successful to modified this robot, and engine robot alsoways come to facebook to save all the information.