Earlier quoted context omitted.
Yes, but the question is how to achieve portability without infringing on others' privacy rights. If I'm on facebook and want to export all my comments, that would require exporting all the status updates of the people who's posts I've commented on, which then also includes those contacts, too. There's no such thing as exporting a single node in a network, you need the entire network.
You certainly can export a single node - just depends on your expectations. For example, the Indieweb has already done this in a way that I find acceptable. My blog (kickscondor.com) syndicates all the comments to every post (including deeply nested ones.) And it also captures a copy of all posts that I respond to (all the way up the chain going backwards.) This is sufficient for me. No need to export anything - it's…
What does this mean?