I do something that increasingly rare for a cashier: I check the signature on credit cards against the signature on the receipt. Too many times I have purchased something, usually with a self-swipe kiosk, and held out my card, face down, only to be ignored by the cashier. How do they know I am me? I always use my bank card as credit because my bank charges me to use it as debit, so I run into this signature scenario at almost every store.
When I'm on the other side of the counter, I often go to check the signature and find that the card is blank. Thieves dream about wallets filled with unsigned credit cards just waiting for your name in their handwriting. I cringe when I go to compare the signature and find a big empty space. I always mention it to the customer and suggest they sign the back. At the very least, write SEE ID. Nine times out of ten, the cashier still won't ask to check your license. But at least it's not a free-for-all in the signature line. Not to mention that credit cards state "Not valid unless signed."
Personally, my cards all bear my John Hancock. My husband prefers to write SEE ID. In these times, when many purchases are online, the signature line almost seems superfluous. But there's no way I'd leave mine blank.