Mastodon proposes another non-private privacy scheme. I don't think this leads anywhere good, other than users ending up confused and sometimes doxed. Times are tough, and fake privacy may really put some people in danger. Mastodon doesn't need to do all the things, and most people are already using good enough private chat systems which genuinely implement public key encryption. Just add a way of linking to that.
@bob I don't think federation and privacy mix well.
@tuttle @bob @gargron Federation and privacy _could_ work together. The problem with this and other #OStatus private messaging proposals (and the #ActivityPub proposal, from the little bit of reading I've done) is that privacy is an afterthought, cobbled onto something that was not designed with privacy in mind.

That said, I recently had to use Twitter DMs to convey a limited distribution message to someone on another instance that should have been possible to send from here. Some things don't need to be private forever, they just need to be reasonably sure that the intended recipient can read and act upon them before the contents become public. (That is about where Twitter / Facebook / $CENTRALIZED_SERVICE DMs are right now anyway. We all know that their admins and employees could be reading supposedly private messages anyway.)
@lnxw48a1 @tuttle @Gargron @bob Yeah I do think there's a place for DMs but it shouldn't result in the contents of the notice becoming public on failure. The proposal does seem to be getting there, though I have yet to examine it in full detail.