the Target hack was not a hack of the payment processor. it was malware that effectively MITM'd the swipes and stored them on target's compromised servers. so whether the cards were stored by the merchant or not would have been irrelevant.

> If processor is hacked and their credit cards on file are stolen, yours will not be one of them.

i'll put my money on the merchant being hacked before a payment processor whose business IS data security.