http://ficoforums.myfico.com/t5/Credit-Cards/Amex-Verification-Fraud-Alert/m-p/3334614/highlight/tru...
http://ficoforums.myfico.com/t5/Credit-Cards/Amex-Account-Frozen/m-p/93372/highlight/true#M19409?fil...
Apparently, it isn't all that unusual. I have only ever gotten phone calls from them making sure it was me before they allowed the payment to go through. I understand this as I travel a good amount for work and charges appear from all over the U.S. I have never had my account frozen though. In fact, the last time this happened was in a grocery store in the Atlanta area 4 months ago. Put the charge through on my PRG and it was declined. Used my Delta and it went through no problem. Got out to the parking lot and got a phone call from Amex Fraud Dept wanting to verify that it was me using the PRG. Told them it was and everything was fine.
