It used to be that banks would compare signatures to approve/decline checks. What are checks you ask? Exactly!
It used to be that tellers would compare signatures from the back of your card to the signature you just scribbled on the receipt to ensure it was really your card. (when's the last time if ever someone asked to see the signature on your card or compared the card info to your gov't issued ID?) Now, the PoS units have digital pads for signatures. Has anyone anywhere ever had their digital signature look anything like their written signature? I've never signed a digital pad the same way twice.