Too many people do not understand how the licenses work.
The Smithsonian ran the photo captioned as follows:
Photinus pyralis, a species of firefly found in the eastern United States (via wikimedia commons)
No mention of the photographer. Just a link to the Wikimedia Commons database.
Crediting Wikimedia Commons for an image is like attributing a Mark Twain quote to "The Public Library". A repository is not the source. Wikimedia Commons did not spend hours creating a technically difficult photograph of an insect in flight. Terry Priest did, and Terry Priest deserves the credit.
This is not just an etiquette breach. Both Wikimedia Commons and Flickr give the following terms for distributing Mr. Priest's work:
Pay attention to the bit about attribution.
With the photographer uncredited, Smithsonian has not followed the license conditions and is in violation of terms. The firefly is still a copyright-protected image. Creative Commons is not a copyright-free zone. With Smithsonian operating outside the agreement, they have opened themselves up to an infringement lawsuit should Mr. Priest be feeling litigious.
I don't mean to pick on a fine institution like the Smithsonian. Nor am I suggesting Mr. Priest ought to sue, although he's legally within his rights to. I'm just using this as representative of the Creative Commons abuses that are rife on the internet.
Creative Commons is a good thing. I would like the organization to succeed. Ultimately, though, the accumulated misattributions of Creative Commons licensed materials are bad for everyone. The more that content distributors take without giving back, the less incentive creators have to feed material into the system. If open-source art is going to work, users need to be partners, not parasites.
*update (2:50pm): Smithsonian has corrected the credit