It's a personal battle for me. I don't have a Facebook account nor twitter. I do have a linkedin profile and participate in several forums. That being said, I don't outwardly just put info online so anybody can peruse. I'm in the process of getting away from the "free" email providers because they are very insecure and knowingly share and sell your info. Yes, alot of your info is out there, but you don't have to be ok with it. I believe if you are pro-active you can reduce your footprint on the net to a reasonable level.
Don't even get me started on Facebook!
Facebook Privacy: A Bewildering Tangle of Options - Graphic - NYTimes.com