Paul Jacobson writes at iCommons.org on Why bloggers should use Creative Commons licences. Check out Jacobson’s extended argument, the core of which seems to be that unfortunately fair dealing/fair use will sometimes not be enough to avoid legal roadblocks to conversation; out of respect to your readers, bloggers engaged in conversation with you, and the health of the blogosphere, please explicitly grant more rights by choosing and applying a Creative Commons license for your blog.
Bloggers were among the earliest adopters of CC licenses. If you have a blog and you’re reading this, chances are you’re an early adopter. If not, get on board now. If so, think about how Jacobson’s argument applies even more strongly to other conversational media, e.g., vlogs and podcasts, or consider choosing a more liberal CC license than the one you’re now using.