It has been the law for centuries that dormant bank accounts escheated to the state. Escheat is an old concept at common law that deals with property without an apparent owner—in essence at common law “someone” must own all property and there can be no ownerless property.
In the case of a dormant bank account, the state is supposed to try and locate the owner and his heirs so as to turn the property over to the lawful owner(s). If no owner is found within the specified time, the state keeps it.
In the case of the store cards, there’s arguably a case that the store is the residual owner, if that’s what the gift card contract provides and if the original owner can’t be located, which one would expect is normally the case for an old gift card. Of course, the entire concept of “contract” between the store upon which the card is based and the purchaser and the card holder (not the same person as the card purchaser) is murky to say the least, particularly considering the number of parties involved, as the card might be purchased at yet another store.
When I was practicing law and had a major cellular operator as client, I was concerned that the pre-paid phone cards with residual value after the expiration date would escheat to the state, and it seems that may well be happening now.
Jack