Well, Mark Zuckerberg, CEO of Facebook, after stressing many times in the past how important privacy is to Facebook, has revealed his real thinking concerning privacy: he feels that social norms are changing and people are beginning to be more accepting of sharing personal info online, and so he is just adopting this norm, hence the recent privacy changes on Facebook that defaults your personal profile as public instead of as private.
If social norms are really changing in the direction Zuckerberg mentions (perhaps because a newer and younger generation of online users do not quite fully understand and/or care about all the ramifications behind sharing personal info online), then we are in for a very interesting decade where privacy issues will rise to the forefront of social issues, no doubt fueled by social sites weak on privacy concerns like Facebook.
We predict Facebook will get some real competition soon from another social site with a more cautious privacy policy.