Eh, newsgroups aren't all that different from email. The newsgroup message format is the email message format, just slightly stricter, and newsgroups can largely be treated as read-only folders (especially if you can equate cross-posting to something like X-GM-UUID mapping a message between multiple folders). It also turns out that many mail clients already support yEnc and uuencode--I've seen email scanners scanning yEnc attachments before.

The tangles come from poor separation of low-level protocol/parsing code with the front-end logic--there's no way to parse a message (or even decrypt it) without displaying it at the same time, for example.