[lisarea]

Facebook was originally pretty walled in, and was used primarily for college students to communicate amongst themselves, and it expanded to include other groups in increments. I don't know whether it was explicitly stated* or anything, but getting people to use their real names was very much a matter of trust not very long ago. A lot of people were only willing to do that because they believed that it wasn't going to go beyond that.

I don't think it's unreasonable for users to be able to opt in, rather than out, of having their information disseminated beyond what they initially signed on for.

* Most of the time, I try to extricate myself from social obligations rather than seeking out new ones, so I've never even considered using Facebook long enough to look up their terms or anything.**

** Ha ha!