The practical impact of import restrictions should be made crystal clear with these words, "No Shipment to the USA."
This German dealer will no longer ship this Syracusian Tetradrachm to the USA, presumably because of import restrictions on "coins of Italian type." See
http://www.vcoins.com/grotjohann/store/viewItem.asp?idProduct=820
There is no indication this coin is a "fresh find." Indeed, given its toning, this coin has likely been in a collection for years. Yet, since the dealer has not identified this coin as being pictured in an auction catalogue or price list dating from before the restrictions, the dealer cannot ship it to the USA lest it be seized by US Customs and returned to its presumptive supposed find spot, the modern day Republic of Italy. (Though US Customs is supposed to accept certifications that such coins were out of the country before the date of restrictions, even where this information is available, Customs has been known to reject them absent auction catalogue citations.)
Yet, the same coin can be shipped to collectors ANYWHERE else in the world, including within Italy. How then do the restrictions comply with the CPIA's "concerted international response requirement" that was meant to the ensure the comity and effectiveness of import restrictions and also thus preclude any such discrimination against American collectors?