Comments? I think Imran has a point.
How about adding a column img_license to the image table and requiring the user to specify a license during upload:
* Public domain image * Copyrighted, used with permission * Fair use * FDL * FDL-compatible license (could be listed individually, if we have such a list)
That way, we can keep track of the licenses in use and remove all images under a specific license if problems with that license arise. We can also add a standard text to pages containing images that are not FDL or PD ("The following images on this page are not licensed under the FDL and may therefore only be distributed, but not modified: foo, bar"). This is much better than manually adding a copyright notice to each and every image, trying to keep track of which images are PD and which are not etc.
This might make things a little more complicated for image uploaders, but we already have a copyright checkbox anyway, so I don't see why we shouldn't use a dropdown instead to gather meaningful information.
Regards,
Erik