I was not successful however in triggering this to find images on some of my sites using the site operator (like for site:blogoscoped.com), either for sites using rel="license” or an rdf meta comment. Using the site operator for Flickr did work though. I’ve asked Google for more info.
Naturally, by using a CC search you can’t guarantee that the content you’ll find is indeed free to use legally... because someone labeling it as CC might not have had its copyright to begin with. Google on their help page on the subject disclaims “By returning these search results, Google isn’t making any representation that the linked content is actually or lawfully offered under a Creative Commons license. It’s up to you to verify the terms under which the content is made available and to make your own assessment as to whether these terms are lawfully applied to the content.”
[Thanks Dpic → Google OS!]
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