However someone questioned why the Getty was returning greek artifacts to italy, so i was looking through wiki about the two named items. The Aphrodite one they are returning is from a Greek settlement on Sicily, so that one's a bit tricky. However the "Victorious Youth" article above says that it was reclaimed from a shipwreck, probably of a Roman vessel returning home with looted goods.
So Italy is pissed that the Getty is unjustly stealing what they rightfully looted :)