If we really wanted to be nutty about IP law we could have taken down all the Abu Ghraib photos, as they were put up only on a prima fascia claim of public domain -- which assumed that the models/photographer's claim of "official duties" would stand in court. AIUI, according to military law rulings, those soldiers were not performing "official" duties. :) Would we need to go visit the photographers in prison to inquire if they want to release them under PD-GNU-CC?
I thought the doctrine of equitable estoppel prevented a party from making one claim in one court case and then making the opposite claim in another court case.