I had a case where the issue was if the work had been previously published invalidating the US copyright.  This case will be very useful for showing no publication occurred if the work was only posted on a foreign website.  In Moberg v 33T LLC (D Del 2009) 666 F Supp 2d 415, the district court held that a work posted on a foreign website was not “published” in the United States for purposes of 17 USC §411 and therefore did not trigger the registration requirement.