User blog comment:Semanticdrifter/The CC-BY-SA License and You/@comment-954127-20120717222227/@comment-26686429-20120717222759

(I'm not a lawyer, but here's my take on it):

When you add content that you made to the wiki, you license it under the Creative commons license.

When you add content that you don't own, for example an image that's a screenshot - then that has to be fair use, as you don't have permission to license it under CC. Text can be fair use too, for example - a quote from an article.

It gets more tricky when someone edits the image. That's where image licensing templates come in. Typically - a user may choose to license the stuff they did under CC, and leave the original work under fair use. The copyright for an original work remains with it's original author.