A couple weeks ago gMail had a failure where thousands of people lost their account information. They lost all their messages, inbox and sent messages, they lost their address books... one could argue they lost their lifeline to the universe. It's the old question of backups, but with a lot of these online services, you can't back up the data, so the question is, who owns your address book? Who owns your friends?
My friends on Facebook ARE my friends, for the most part. I'm careful about who I connect with on Facebook because, aside from posting my professional blog there, I also post photos of me dressed as Santa with a beer in my hand, organize social gatherings, and make comments to my mother. Not the kinds of things I really need my clients tapped into.
If I lost all my connections on Facebook, I could rebuild most of them because I have a real-world connection with most of them. And I pretty much know who my friends are on Facebook -- there are exceptions, sure, but then there are people I've lost track of in the offline world who I later remember and say, "Oh, yeah... I kinda remember them... we were pretty good friends years ago... whatever happened to that guy?"
On the other hand, @JokeIndex's 3,000+ followers aren't really my friends, they're Twitter's friends and I just get to borrow them. Even if I made a backup of everyone who's following me, I can't force them to follow me again, and the likelihood of them bothering to find me is probably slim.
There are people who have invested a huge amount of time in making "friends" or, rather, making little connections in someone else's database. But if all those connections are on Twitter or Facebook or Google or anywhere other than a file that you can use regardless of the state of the cloud, then they aren't really "your" friends.
That backup file can be in your brain, like my Facebook friends, or it could be a big, professional database, like the kind Conquent seems to be constantly building. If you're making "professional friends" or "business contacts" that are all through LinkedIn or Xing, you're not building a resource for you, you're building a resource for LinkedIn or Xing.
But, if you really want to keep friends, you have to make friends. And I don't mean followers, connections, contacts, peeps, or whatever you want to call them today. Friends aren't something you own, anyway, they're something you nurture and create over time. And when the revolution comes, you'll learn pretty quickly who your friends are and who's just someone else's intellectual property.
Live by your wits, until you get the flu
Agonies of Programming for Facebook