[not_that_noob]

Very interesting. The big concern here is what exactly happens in case of fraud. With credit cards, this is less of a hassle for the consumer, since the issuer takes the hit. With debit, it's a pita to get your money back if it's stolen. I use my debit card only at the ATM for this reason.

[jonbwhite]

Yeah, it's unclear what Square's responsibility is in this situation, especially since they are indirectly performing transactions on your behalf.