The value of information has been decreasing over time. How do you see this isn the real world? There are two ways, one can be seen from the user perspective and the other from the attacker/bad guy perspective.
From a user point of view, the most obvious method to see information devaluation is Facebook, Twitter, MySpace, Linkedin etc. These may be seen as good ways to keep in contact, but look at all the personal data stored in these sites. Enough to authenticate to your bank account with such pieces of data as Name of Dog, Elementary School, Parents Lastname. Everything for secret question authentication. There was just a theft from a bank (http://www.networkworld.com/news/2009/092409-construction-firm-sues-after-588000.html) where the challenge questions were successfully answered.There are many Network security assessment tools to prevent such phishing ways to get the answer to these challenge questions.
The attackers are focusing Phishing efforts on Twitter and Facebook much more these days. Its pretty obvious why, so much information is available here. KRAA Security a Network security audit tool provider twitters, but we try to keep personal things off there. But many people lives their lives on twitter so much, its a mind boggling concept.
So is there is a solution the phishing problem in Social Media? Probably a security penetration test for such websites. Even though the phishing problem will probably get such more extensive as Social Media expands, takes over more aspects of our lives and invades every information dissemination media. Doomed I say.