I've never understood the paranoia about 'the man' knowing your information. It's all stuff they can find out anyway. So what do you do? Live your life in paranoid fear, never 'networking' incase the wrong people can find out about you? Well give me a break... sometimes that just keeps the right people from finding out too.
I'm on FB.... and I just don't fill in all the details, affiliations, daily info, place of work, home phone, etc. It's the internet after all, and even if the owners weren't mining info off it, someone else could be, without all the straight forward disclaimers.