Creative Commons licenses provide a standard way for authors to declare their works “some rights reserved” (instead of “all rights”). If the source you’re quoting has a Creative Commons license or public domain dedication, you may have extra rights to use the content.
Licenses don’t trump fair use, but if you want to do more than fair use allows, look at the terms of the license to see what it permits and what, if anything, it requires you to do in return.
The attribution license for example, lets you copy, distribute, and display a work so long as you name the original author. Share-alike lets you make derivative works so long as you use the same license for your re-mix. A work in the public domain is no longer under copyright, so you can use as much as you want in any way you like.
Posted in: Questions About Copyright