I don’t know. I’ve wondered that myself. I’m afraid someone who’s been here longer than me will have to answer it.
(Here’s a relevant post from some time back that talk about this as well: RFC 55 - Unpublished ImmutableData - #10 by happybeing)
But I’m totally with you there, everything leaving the client should be encrypted. So, that’s what I’m advocating based on what I know.
Maybe there’s some use case when it’s not important, but it should be opt out then IMO.
Edit: I’ve been informed that this task is on the roadmap: Safe Network
I’m not sure of the scope at the moment, but at least that would cover the data-at-rest part. Then there is in-transit. But that feature would be a major part of addressing this issue. Let’s await the guys who knows this, and they’ll probably enlighten us on the subject.