When I called AMEX telling them I do not like the fact that there is no PIN number for even high transactions with a merchant in-store, the operator said that AMEX can also detect fraud if somebody uses my (lost) card. I am not sure I believe that.

I requested to have a PIN number added to my card, went through a verification process and was told that now I will need to use the PIN number to buy anything. Not true. I still can use the card anywhere I want for whatever amount, without any limits. And nobody even looks at the signature strip where it says “PHOTO ID”.