You know how the old story goes—a frog jumps into a pot of water. The water is the perfect temperature so the frog starts swimming. Slowly the temperature rises ever so gradually, little by little. Eventually, the frog is cooked. As the tale goes, the cook avoids having the frog jump out of the pot not by throwing the frog into boiling water—the frog would just leap out.
Enter Facebook's "boiling frog" strategy. They know that people will naturally over time live more public lives and feel comfortable with it. But, they have to turn up the heat of privacy settings very slowly. Consider the newly released Instant Personalization feature. It allows certain non Facebook sites to access certain personal information. Of course, you can turn off the setting. But that's the point. It's default setting is turned on. Frog, meet water.