Visa & MC policies can be a little hard to pin (pun intended ) down, since they don't like to publish them in any solid fashion--something about accountability, most likely.

In any event, the law of at least some states specifically allows retailers to request ID when you use a credit card, e.g. California Civil Code section 1747.8 (see, e.g., http://www.dca.ca.gov/legal/p-2.html). However, to fight ID theft and for privacy reasons the retailer may not write down or record (or ask the card user to write down) in any way any personal ID info--a law often honored only in its violation.

This is a very interesting thread--people, even FTers, a rather well-informed group, appear to know, on average, little about the dangers of using EFT cards as opposed to credit cards.