The first rule when you want to give a donation to someone is faith, you can't know where your money will go since there's no way to verify it. Even though someone have post an images if the money is used for good thing, there's a chance he doesn't use it all and took some part of the money without anyone know. After all, you need to trust the person you donated, in this case I trust Yahoo and he doesn't obliged to give any proof to anyone if he have a reason about it e.g. privacy concern.