SSWs present some very interesting opportunities (and challenges) from a copyright perspective. As soon as you allow the remixing of content in your SSW, whether it’s content you created or submitted content you published, you have to decide what kind of legal license framework you want. Ideally, this will be shaped by your goals for the SSW and the kind of experience you want to create for audiences. And, ideally, you’ll seek legal guidance from an attorney.
Some creatives want to maximize collaboration and remixing of content, so they construct legal frameworks that support this kind of SSW. Others prefer a more conservative approach (e.g., the SSW owner retains complete control over all content) with select invitations for audiences to contribute being issued in very managed and controlled ways.
Whatever you decide, default copyright is both country- and state/province-specific, so you’ll need to get appropriate legal advice on what applies to you and your SSW.