:') If the artifacts were looted after the international ban on laissez' faire antiquities trading (as opposed to what went on during the European colonial period), they should go back. One problem of late has been that unsubstantiated claims that pieces came from looting has been recognized as legal claims.
These days, a lot of unsubstantiated claims are growing legs and walking. If we don't wake up, they'll be talking soon and they are so impossible to silence.