The point of the public domain is that anyone can do anything with it, including sell it, so in a way, it makes sense that the Corbis image-library is full of high-priced Library of Congress images.
But it's also unquestionably a ripoff to sell people things for $1,735 (the price for getting a Corbis license to a public domain LoC image in TV and online) and not bothering to mention that you can get exactly the same image, absolutely free, from the Library of Congress itself.
We want people to build services that add value to the public domain, making it easier to search and work with. Corbis's clip-art search is pretty good, but no better than Google Image Search, the Internet Archive, or Flickr's search (all of which index the LoC and allow you to restrict your search to freely usable work).
I mention Corbis because I was stunned by the number of free public domain images it sells, such as this image of the turret of the battleship USS Monitor. Corbis will sell you this image for between $110 (for internal use only) to $1,735 for TV and Internet. Exactly how they get to 1,735 and not 1,700 is a mystery. The bigger mystery is how they sell it at all, as this same image is available for free from the Library of Congress. It's the picture at the top of this column.
In fact this whole page appears to all be images ripped off from the Library of Congress with no attributions.
Does Corbis ever tell its customers that these images belong in the public domain? I see no evidence of it. Because of the outrageous prices for something that should be free, you assume they own the pictures somehow. It's impossible to own these public-domain images. The company should be ashamed of itself.
Stock Photos Will Drive Photoshop Use Into the Ground [John C Dvorak/PC Mag]