Letters, Digits.
> That one's easy. You send him a message and include some of the shared information.
Not so easy if their settings prevent this - you can choose to receive messages only from friends. You can attach a message to a friend request, which can be locked down as far as friends of friends, IIRC, but then being able to send such a message assumes you do have mutual friends on Facebook - which might not necessarily be the case, if the other person has only recently joined. Or it could be the case if the person is a nasty mean grumpy bastard like me who at one point got so pissed off with his friends and family proliferating panic-status updates and so on that he deleted everyone then started again.
> You agreed with the comment about protecting private information by not giving it to Facebook.
> Not so.
Yes, yes I did - and I stand by that.
> Trivial counterexample: One of actual friends (not to be confused with the debased sense of > "Facebook Friend") posts a group picture and captions your name.
You can caption any picture, anywhere, with anyone's name, so I fail to see the relevance. If you mean tagging, which is slightly different, then if someone tags your name such that it is linked to you, you can detag it - and they won't be able to tag it that way again. They can tag it without linking it - but that's really no different to a caption.
> Ugly (but not nearly the ugliest possible) counterexample: Scammer steals some of your
> personal information and creates a fake Facebook page in your name to scam your friends.
Interesting concept, but unless someone joins Facebook and connects with their friends and family on the site without ever mentioning it to those they are in contact with currently, in the real world (which somehow seems natural to me, but maybe I'm just a little bit crazy) then I think it's a non-starter.
Only once someone has established contact with a good number of their current real world friends and family should they be thinking about contacting people they once knew, a long time ago, IMO - but then that brings us back to your first argument; about contacting people and asking if they're the Joe Bloggs I knew from x years ago: If that's a scammer, pretending to be Joe Bloggs, then he might say yes anyway intending to scam me. Having an open friends/mutual friends list is therefore more secure by your own example, isn't it?
> Someone needs to create an alternative system that starts from a Golden Rule of Privacy Principle.
Good idea. Let me know when you've got it up and running, and I'll think about joining it.