i generally find it amusing when people from other countries mock the US for not having PINs. this is just another way of saying "my country has high fraud rates and yours appears not to." :-) . you can see this in the comment below "If we were swipe-based here, we'd all bebroke :-).". the payments systems are architected to minimize cost and maximize adoption and they are usually at (or moving towards) some locally optimal point. the US is no exception in that.