Let me tell you that you shouldn't feel too bad about yourself in that way. I recently was trying to articulate exactly how the defaults work on Facebook. I have talked about this for two years straight. I have students who live and breathe and consume the sugar of Facebook every moment, as do I, and I could not do that for you.
In order to articulate the current defaults for Facebook, we actually had to sign up a new identity and go through it from scratch, because in the past two years since I started talking about this issue, they have changed so many times which things default to friends only, which things are to friends and friends of friends, and which things are to the public. Those things are changing so frequently that I'm not surprised you haven't been able to do it. I haven't been able to do it either.
This is why I think we need some kind of a benchmark or an anchor. I think you should ask them exactly how they go about deciding whether to roll out these changes to the defaults and really what is going on there. I think you'll find what's going on there, if they answer honestly, is they want to collect more information, rather than less information. If the defaults stack towards giving them more information, they will do that. That's how they've engineered this whole thing. It just did an end run around everything our Privacy Commissioner had tried to do with them.