With regard to the settings on Facebook, we try to be very clear with people about the way that settings work. A centrepiece of the way in which our service operates is what we call “inline” privacy controls. That means if you put a piece of information on your timeline, right next to it you'll have a button that will allow you to choose who will be able to see that information. In some cases, the default, meaning the setting that it's at when you first create your Facebook account, is public. Then, too, there are other situations where it might be something other than that.
In general, our view is that providing information publicly helps people to communicate and connect. We think there's real value in enabling people to share. When you look at other social services on the Internet, you see that many of them are generally public by default. We think encouraging people to engage in a public discussion is helpful and promotes our community.
That said, we think it's also important for people to make their own decisions about what information they want to share and with whom, which is why we see a lot of use of that setting. We see people who choose to share their information with friends, or with a more narrow group in some cases. Some people choose to post things to “only me”, which is the setting we use to suggest that only you will receive that information. You can remember it for later and have access to it, but it won't be shared with other users on Facebook.
We think providing a platform that enables social integration but that also empowers people to make their own choices is the right approach.