Digitized Signatures

At several grocery stores, I have to sign my credit-card receipt on a “signature capture pad” such as this one. My signature is stored in digital form “affixed” somehow to the receipt. What purpose does that serve? With ink signatures on paper receipts, it is hard to forge or transfer signatures onto bogus receipts. But as for digitized signatures, what prevents the grocery store from “affixing” my digitized signature onto any other arbitrary receipt?

A client could be duped by the store with bogus charges. The store could be duped by a client claiming that he or she never signed that particular receipt.

If the courts assume that these capture pads are trusted devices and that it would take too much trouble to store and paste signatures onto fake receipts, the store wins, and the client is at the mercy of his or her credit card company. On the other hand, I am often amused by how terrible my signature appears on such capture pads. Perhaps clients have an easy out in that case, since the captured signatures look far from authentic.