Could someone with a bit more understanding of "normal" people explain why this is? There are many cases where people seem to throw caution out of the window just because they're on the Internet. It doesn't make sense to me.
You could even try to reconstruct foursquare locations of people who are not on FS just by their FB buddies ... try to explain that to "normal people".
And isn't it a bit scary that you seem to need more and more caution as time goes by? Would we need more responsibility on the side of the makers or do we keep blaming "normal people" for the world we create? (like we do it with, let's say, their inability to maintain secure passwords?)
And you raise a false dichotomy. Just because someone wants to exercise their right to privacy does not imply one is in "constant fear" of others.
How does your public identity being tied to your "real self" helps you if some random person decides to break into your house? How would you feel if people you don't even know started shouting "Happy Birthday" to you on your birthday? How would you feel if those same people started talking about those genital warts you had to treat two years ago?
People will be comfortable sharing anything (identities, actions, personality traits) as long as they feel they have control over who gets access to what is being shared. I fail to see how anyone would feel comfortable sharing everything to everyone.
All I'm trying to say is that I don't see how to reconcile the idea of having a "public lifestyle" (i.e, let personal information be freely available to anyone that bothers to go look for it) and being able to have a controlled disclosure of personal data.
You raised concerns over someone breaking into my house. I believe we want to stay away from the "you should be afraid of people" argument.
So I suppose your concern is that I would rather some information I leak out remain private. Sure. So what? Then you have to worry about things that you wouldn't want an acquaintance at a party to know. What are those things, how would they get online, how often, and what would the impact be? It's better just not to worry in my opinion, instead of running around putting out fires when a friend of yours on Facebook or Twitter publicly posts that it's your birthday.
But the whole point about the OP that started this discussion of ours was not about information that people are comfortable to share with people they trust. It's about how people not realizing about the information leaking to people they don't know. You seem to dismiss that with the idea that it's a false sense of security. We could argue about that, but it's besides the point.
What I wanted to point out is that it's not just about security. It's about trust. And trust does not with blacklisting post-facto. It works by whitelisting prior known people. The people who got surprised by discovering they were visible on some creepy website had to learn that the hard way.