I left Facebook a long time ago not only because of the privacy reasons, but
also because Facebook was inconvenient for me. When I found that Diaspora was
convenient to me and not a privacy nightmare like Facebook is, I logged back
into my old Facebook account (being sure to allow cookies only for that
session) to tell some people I had been connected with there about Diaspora.
I didn't get a response. I don't know if it's because my posts somehow
weren't seen (I noticed that the first post I made to my own "wall" was set
to "private"; I don't know how it works for stuffy you post on other people's
"walls") or they just weren't interested.
One thing that was interesting, though: every time I logged into Facebook
recently for this purpose, Facebook said that it didn't recognize the device
that I was using and made me go through an authentication check. I suspect
it's just that the site relies on cookies for that, but interesting
nonetheless.