can't be hacked. apple never has the credit card number. Only your device has the credit card number, and even then, it's stored on a locked down chip inside your phone. It's not even stored in memory, it's pulled directly from the RAM on the NFC chip.
Then there's the fact that you need a fingerprint.
Get this: even if you had the fingerprint, you'd still have to have physical access to the phone, and hope the owner has not noticed it's missing, to do any sort of fraud or data mining.
And even if you had physical access, in order to data mine, you would have to tear the phone apart, Desoldier the nfc chip, and rip it's contents. But guess what? its all encrypted.
I know a lot of you don't like apple and i'm with ya on a few things, but you have to appreciate just how flawless the security of this system is. You can keep waiting for hacks, they won't happen.