There's been a lot made of the oversharing which occurs with teens and 20-somethings on Facebook and other social networks, often painted as a generational change.

For those of us who were alive and tech-conscious in the 1990s, there was a very similar trend, though rather smaller (as the Net and Web were also much smaller), of a small number of high-profile "online diarists" who shared, often fairly compulsively and excessively, life details.

Some remain online, some have largely disappeared, some are much more muted than previously: Eve Astrid, Xeni Jardin, Rebecca "Net Skink" Eisenberg, Violet Blue, (many were notably women), and some of the early bloggers: Dvorak, Ito, Weiner, and others.

Andersson at last check worked for Google. Jardin continues to blog for Boing Boing, though more quietly since a dust-up with Blue and recent breast cancer diagnosis. Eisenberg is corporate counsel at a tech company. Blue continues her sex blogging, though less prominantly than I recall. Life, jobs, relationships, breakups, kids, and the like, tend to take the edges off over time.

It's something I'm presuming FB and G+ will discover over time. Google's approach has been more nuanced in part, I suspect, as its creators were more mature than Facebook's.

Past age 35 or so, the most voluble social networking types tend to be those with a vested interest in noteriety. Mostly marketers, entertainers, other media types, technology evangelists, CEOs, and VCs.

You don't need to be able to take your data 'out' of Facebook to use it in contextual applications. That's what they have an API for. For example, Highlight can look at all my likes and compare them with the likes of the people around me to show me people with whom I have similar interests.