Earlier quoted context omitted.
The main thing Facebook provides that isn't addressable with the systems we'd be left with in a "rollback" is a universal way to stay linked to other people that provides both people with control over whether that link exists or not. Everything else is just features glommed on top of that basic feature. AFAICT there are only two ways to provide that basic feature: (!) A centralized service like Facebook that manages…
I am still trying to work out why something approximating (2) can't be done through a simple combination of: - tried-and-tested public key cryptography techniques - using e-mail as a buffered delivery mechanism (everyone has an e-mail account that can store plenty of messages until they're next on-line) - borrowing the typical DVCS copy-the-whole-repo approach so you've got distributed back-ups - writing a native cli…
PS it will be completely F/OSS, most likely GPL depending on contributor consensus.