It makes me wonder why CC companies bother having the strip on the back still? It seems to have little value these days, and the 2 most common actions (leave it blank or sign your name) both have problems. Removing the strip (potentially just putting the below phrase on there preemptively) seems more sane. Of course, that’s assuming a non-cynical view of CC companies and their relationships with theft/fraud.
Here’s our official advice on signing the strip on the back: Don’t sign it. It’s useless as a deterrent, as anyone who takes your card then has a sample of your signature which they can not only use on any charge slip, but on your checks as well. However, do not leave the white strip blank. In that space, write: “Ask For Picture ID,” and be prepared to back that up someday when you’re in a hurry and the clerk wants to see a driver’s license as well as the card. It makes the charge transaction a little longer, but a lot safer.
Source: The Straight Dope Mailbag