Does talking about privacy make people less willing to share?

Security guru Bruce Schneier recently blogged about some studies that seem to show people are more willing to share personal information when they're not reminded that their information will be kept private.As many of the commenters pointed out, one of the studies was skewed by the fact that people were given a fun-sounding, casual survey, and then one from an institution that might actually do something with the answers. The genius of Facebook and other social networking sites is that they've made people feel that social networking is as casual and non-threatening as a stupid online quiz, when those of us who care about privacy know that all the information we're providing on those sites could be used to hack into email accounts, could adversely affect employment opportunities, etc., etc.If you look at a service like Mint.com, though, which requires the user to link their financial accounts, you can see that the promises around anonymity, privacy, and security are much more upfront.  Facebook may have a marketing incentive to bury their privacy tools; Mint does not.So the issue to me seems to be, how do we get people to realize that their data on Facebook is as important as their data in Mint?  And who exactly is behind those, "What kind of underwear are you?" quizzes on Facebook, given that they get access to the users' Facebook profiles, and what they want to do with that data?