Blog anonymity

I wonder if sometimes I should tell people I know that I blog. That way they can read my blog and really keep tabs on me. Ya know, like family and close friends. But then I quickly remember that if I give out my blog address then they WILL read it and then I'll feel like I'll have to watch what I say, so then this blog isn't really the release that I want it to be. I wonder if other bloggers feel the same way or do they let their friends and family know their blog? I guess it all might depend on the purpose of an individuals blog, is it to inform family and friends of what's going on or can it be a place to write down things before they become public-emotional-outbursts!