The point of Facebook is so people CAN find you. It was originally designed to be an online yearbook for Harvard University, then expanded to other colleges, then worldwide. There are over 500 million users.
I like that I have found almost 100 of my high school classmates, a bunch of cousins I had lost touch with or never met because we are spread out across the country, friends that moved away, former coworker, neighobrs, etc.
You can be just an observer.... you don't have to post anything. You can adjust the privacy settings so that only "friends" that you have accepted as friends can see any info, that is if you entered any info.
I'm hoping that some long lost rich relative with no children will find me and will their entire estate to me. LOL :-D