A critique of federation (in the technical sense).
https://fieldnotes.resistant.tech/federation-is-the-worst-of-all-worlds/
Are privacy concerns inherent to federation? Dunno. The idea of decoupling data ownership from applications is good though. It reminds me of Solid and its data pods idea.
https://ruben.verborgh.org/blog/2017/12/20/paradigm-shifts-for-the-decentralized-web/
And of course indieweb which I commented a while back Solid reminded me of but surprisingly the Solid peeps made no reference to.
https://doubleloop.net/2018/01/09/paradigm-shifts-decentralized-web/