Who's gonna call me out on it? The waitress? The guy working the register at Walmart? What the hell do they care even if they do know? It's not like the credit card company is sending out spies to check and see if people are complying with the user agreement by signing the back of their credit cards...
I was at a PO once and the guy ahead of me had that written on the back of his card AND THEY REFUSED TO ACCEPT THE CARD BECAUSE THEY COULDN'T MATCH THE SIGNATURE.
I worked at a credit union for several years and we could not accept a card from a member unless it was signed with a signature, even if it meant waiting for them to ride out their temper tantrum because they couldn't have it their way.
It's for a cardholder's own protection that signature is required. Write see id all over the rest of the area but the card should still be signed.
For clarification, setsail=