Responsive to an identity verifier having proved that an assumed or purported subscriber is, indeed, in possession of a particular communications device, a financial institution, for example, may be confident that a verified and/or authenticated individual is attempting to engage in a transaction. Conversely, in response to an identity verifier determining that an assumed or purported subscriber is likely not in possession of a particular communications device (or cannot be proven to be in possession of a particular communications device), a financial institution, for example, may elect to terminate a financial transaction, for example.