My private history in terms of people in my life who are dead is very easy to discuss. I don't feel those people can be threatened or intruded upon now. But I am enormously protective of the people who are currently in my life, my existing friends and family. That is where the curtain is drawn.
Think about what people are doing on Facebook today. They're keeping up with their friends and family, but they're also building an image and identity for themselves, which in a sense is their brand. They're connecting with the audience that they want to connect to. It's almost a disadvantage if you're not on it now.