It really doesn't make much difference these days whether a card is signed or just says "See ID." If you write "See ID" on there the merchant can't technically require that you show your ID anyways. They can require the buyer to sign the card in front of them. So if the card's stolen the thief can sign that card and then it will match their signature on the receipt.
Store employees (except those at places like electronic stores) don't check the signature panel much anymore and customers swipe their own cards at so many stores. The one place that strictly forbids credit cards with "See ID" is the post office. They seem to be going overboard, even putting up posters saying they won't accept those cards if they aren't signed. You can get the best of both worlds by signing it AND writing "See ID" on it. Still no guarantee against fraud but every little bit helps...
