The mitzvah of hashovas aveidah only applies to an item that belongs to another Jew, if one knows that the lost item belongs to a non-Jew (i.e., one finds a device with non-Jewish music on!) then one is allowed to keep it. Hashovas aveidah is a privilege accorded to one who keeps Torah and mitzvos.
What’s the halachah if one is in a chasunah hall, and he finds an expensive diamond ring, and he knows the owner has insurance, is there a mitzvah of hashovas aveidah in such a case, or can one perhaps argue that the Jewish owner isn’t losing out, and the only person losing out is the non-Jewish insurance company, and since they are non-Jew’s there is no mitzvah to return the lost item?
The Chelkas Ya’akov (Choshen Mishpot 22) has a Teshuvah where he discusses the above shailah and he says, normally one has to pay something towards the insurance, or the insurance goes up for the future, so the Jew is in fact losing out. Secondly, normally there is a certain attachment between the original item, which will be lost if one doesn’t return the item. Finally, even if the insurance will replace the item, at the time of finding it still belongs to a Jew and hashovas aveidah goes after who owns the item, and not after who suffers a monetary loss.
