Lumpyoatmeal saidWhen you use your credit card on the credit card terminal where you swipe the card and then sign. I just do a squiggle in the box. Should I be worried that anyone could forge my squiggle? They obviously aren't validating it like they supposedly do with paper checks.
I think you're not so much proving your identity as agreeing to the terms. Supposedly 20 years ago a credit card company was automatically responsible for fraud; that may have changed for a while, but I think the bad press from security incidents has reaffirmed that.
I do wonder about the paper checks; my own squiggle changes from day to day depending on things like the temperature and whether the cashier is talking to me, and I actually had some condescending words for my branch last time they tried to reject my signature (I was there in person with a photo ID, for crying out loud).
I may be wrong for not being worried about my signature, but I think most security experts would agree that even a good signature is a lousy way of proving your identity. In any event, I don't think your signature will ever be the difference between you being the victim of identity theft and not. I used to write "see ID" on the back of my card in an attempt to introduce photo verification, but nobody even checks that any more. Most of the security work is done by pattern-matching and/or machine-learning algorithms at the credit card company's end these days.
EDIT: It's not even necessarily "security" work; as much as anything, it's actuarial. The algorithms will be designed to keep loss from fraud under a threshold that is cost-effective counting prosecution and reimbursement.