Perhaps Dat simply isn’t designed for privacy—but it’s so close that I think it’s very useful to talk about the gaps. This is a very solid list of how Dat measures up for private groups—compared to an e-mail newsletter.

It seems to me that the main sticking point is that Dat is always accessible to the main network, whereas e-mail is inaccessible to the main network (except through windy routes.)

It occurs to me that maybe this is what Hyperswarm (a project by some of the Dat team) is attempting to add. If you can run a private Dat network, then you could have a shared folder detached from the main network that would be inaccessible. You’d probably need a password on top of that—but that seems analogous to, say, IMAP. You’d still need tools to access it, so it’s all entirely hypothetical, but yeah—cool thoughts, thank you!