Have we ever stated what our policy is on this front? I think we should sooner, rather than later.
Comments and news posts are one thing (kind of) in that most people don’t care about republishing. But what about creative works? When someone posts a song or (part of) a story… What kind of rights does Elsewhere claim?
Clear planning and spelling out of these can protect both the creatives and the site.
Here’s what I think is the relevant section of the TOS:
https://bbs.elsewhere.cafe/tos#3
I am no lawyer, but I think that does a reasonable job of preventing others from profiting from your work, while leaving the original author the flexibility to license the content out as they see fit in other venues.
Hmmm… I shall have to be very careful about which sketches and scores I put up here.
I use the same CC on everything so hum.
I don’t CC anything at all. I don’t anticipate making a living at what I do (and it’s probably a good thing I’m retired), but, if there is any commercial value at all to what I do, I would prefer to retain the right to realise it.
That being said, I would definitely prefer to see a limited term to copyright (20 years would be good). Initially, the intent of copyright laws was to grant a limited monopoly to establish one’s “brand”, in effect. On the one hand, this was to break the indefinite-length Royal monopolies that preceded copyright laws, and on the other, to grant the creators a breathing space wherein they could attempt to make a living at their work without being undercut by robber baron publishers. It was not to guarantee a continuous income stream for three generations.
I personally would prefer my heirs and their heirs to do something useful with their lives (not that they will become rich overnight when I kick the bucket, but in principle, you understand). 
My view is that the second it goes on the internet someone will steal it. The only thing you can really do is ask the thieves to keep your name on it and link you.
I am less concerned about that kind of theft and more concerned about what rights a person retains (can they strike a deal with and sell to another publisher, or does the platform retain exclusive rights) and what rights the platform retains (if the work is resold, can Elsewhere keep it up as “first publisher?”)
If someone nicks something originally posted here and sells it, it’s possible to prove original publishing and thus the theft (timestamps would show it was posted here first and therefore any subsequent sale not by the Elsewhere account holder is therefore fraudulent).
I’m not reading anything in CC BY-NC-SA 3.0 that implies transfer of ownership. I see it as the license that you are granting to Elsewhere, and to the readers of Elsewhere, but I don’t see why that would prevent you from using it elsewhere in other places, even commercially.
In other words, I think the license is intended to place reasonable restrictions of use on consumers of the content, while still permitting use that makes sense in our remix everything, meme-happy online culture. I do not believe it places any restrictions on the creator of the work.
I’d even go so far as to publicly state that I have no interest in owning your work, because I don’t think that’s what we’re about here. Furthermore, the license granted, although perpetual, could be revoked at any time by either party.
Full disclosure: In case you’re not aware, the TOS that ships with Discourse is mostly unchanged here so far. I think it’s a good fit, but keep in mind that no one specifically chose those terms, so they are absolutely up for debate.
I am not a lawyer, and any of the above should not be construed as legal advice. 
There’s that too.
I wonder if a blanket “all rights belong to you and you just give us the right to publish and promote until you don’t” would be acceptable? I think this is how Tumblr handles it.