Also from the How to Contribute page is this bit about the license:
In order for this kind of a collaboration to work, we all have to agree on the terms through which the things we produce are distributed. This means that we need to pick a license. Intergalactic Social and Jupiter’s Ghost are available under a Creative Commons – BY-SA license.
When you upload content to the site, you are agreeing to make it available under the same license. This means that people can remix your content, as long as they attribute it back to you, and as long as they use the same (or a compatible) license for their work.
This also means that people outside of Intergalactic Social can use your content, and those people may or may not choose to follow Rule #1 above. That’s the nature of open content and collaborative fiction, and I want to make sure you’re aware of it before you contribute.
[Rule #1 says: Do not tell stories involving other users without their consent.
This is really simple. You have autonomy over your character, and they have autonomy over their character. If you need someone in your story, feel free to reach out to them, or just create an NPC. ]
and here is where I'll stop pasting in bits from things I wrote several years ago and start saying some new stuff.