Re: "Strafach, in an email to The Register, said it's not clear what Facebook is doing."
Let me spell it out by addressing Strafach's comments.
"They can easily clear things up by explaining more precisely why they collect certain data..."
- Because they are douchebags.
"...and what they do with it..."
- Whatever douchebags do with your data.
"...so I don’t understand why they are so vague about it..."
- Because douchebaggery!
"I do hope they are being respectful of user privacy..."
- You can hope in one hand, sir...
"... and it would be very nice if they clarified that I think."
- But they make more money being complete and total douchebags.
There is only one answer when the product does something other than what the author tells you it will by design. If you are being lied to, either through weasel words in a contract, through misdirection or omission as to how something works, or any other way for that matter, then you are dealing with a douchebag. Take appropriate and immediate action (see icon if this is not clear enough to work with).