I placed a call to Molly Faust, the American Express Vice President of Public Affairs and Communications for U.S. Consumer Card and Customer Service Delivery. She told me that she was already looking into this matter and promised to get back to me.
According to one TUAW reader, a protection-line operator said "the number of calls we've received about this is utterly insane."
More as this develops.
Update: Molly Faust contacted me again and says to emphasize that this is being handled on a case-by-case basis and that the refunds are not an official program or policy.