[lelele]

> From Stallman's blog & email history on newsgroups I could work out:

The problem is: FB has all these things together: blog, e-mail, network of people and surfing habits (inside FB, at least). For you and recursively for each friend of yours.

[pjscott]

And they don't even have to try hard. It would take effort to track down this information manually from blogs and such; Facebook just has it. Don't underestimate what a difference convenience makes.