According to a quick Google search (I’m no expert on copyright law), a sufficiently original email is automatically copyrighted. What constitutes “sufficiently original” seems to be pretty arbitrary.
So I guess if you post a short story, that’s automatically copyrighted. Commenting “this” is not. And then there’s a huge grey zone in the middle.
Should be an option to allow/disallow non-instance users to vote. That’d be really useful here in sh.itjust.works for the Agora.