Re: "Facebook's position is that once they have the data, it's their data"
Oh, it's not just Facebook, Google is at it as well and blatantly so:
Some of our Services allow you to upload, submit, store, send or receive content. You retain ownership of any intellectual property rights that you hold in that content. In short, what belongs to you stays yours.
Looks good right? Here's the rub: you actually do NOT retain those rights with respect to controlling the use of your content/IP/copyright, so that acknowledgement is essentially meaningless - see here:
When you upload, submit, store, send or receive content to or through our Services, you give Google (and those we work with) a worldwide license to use, host, store, reproduce, modify, create derivative works (such as those resulting from translations, adaptations or other changes we make so that your content works better with our Services), communicate, publish, publicly perform, publicly display and distribute such content. The rights you grant in this license are for the limited purpose of operating, promoting, and improving our Services, and to develop new ones. This license continues even if you stop using our Services (for example, for a business listing you have added to Google Maps).
Copyright issues aside, "Right to be forgotten", anyone? Oh, and if you piss off Google you have given them the right to change any of your emails into the opposite - really, you have. No idea if that means you can't sue them for the consequences if they do so, you did give permission..
Our automated systems analyze your content (including emails) to provide you personally relevant product features, such as customized search results, tailored advertising, and spam and malware detection. This analysis occurs as the content is sent, received, and when it is stored.
.. or, translated: they will access incoming email, or, translated, they will access contents for which they have not given permission. Which is something you permitted by using Gmail. I wonder where that leaves you as a business using Gmail, as far as I can tell you are breaking the law.
I need to be in Brussels in the next few days anyway, I think I'm going to prod a few people to have that looked at. Ought to be entertaining (evil grin)..