I don't think that rathboma was suggesting that you might get fraudulent changes on the card - but any other service that you use which currently has that card

I don't think that rathboma was suggesting that you might get fraudulent changes on the card - but any other service that you use which currently has that card on record could now potentially be compromised by anyone who knows your name and has those 4 digits - many customer support systems only need that much to verify your identity and make changes to your account.