
If you want to surf the zeitgeist, then look at the most common queries on Google. When I looked the other day, "How do I delete my Facebook account?" was fourth on the "How do I...?" list. Just to put this in context, number two was "How do I know if I'm pregnant?" You don't have to be Sherlock Holmes to twig that something's up."
There is a wonderful graphic on the New York Times site showing how Facebook's privacy statement has got larger and larger to cover the growing holes in its privacy policy. The mapping isn't perfect: if it were, the declaration of Facebook's dedication to privacy would have to be of almost infinite size, since the default amount of privacy Facebook now offers is practically zero. When the site first started, very few people could join, and nothing became public, even to them, without the users' express permission. Now everyone can join and everything is public to almost all of them unless you make a determined effort to hide it. This effort has to be renewed every six months or so when Facebook revises its privacy policy to make it more opaque and less effective. There is a wonderfully graphic animation of the process at this site.
I'm reading her book The Silent State at the moment, which is a real eye-opener.