AmEx tried to get a larger piece of the CC business when they offered Delta cards and the like to people with credit scores as low as 590, and also tried to force credit card customers to adopt a charge card mentality. Much of their F/R action in the past two years was an attempt to backtrack from those less than brilliant moves. AmEx's F/R efforts have been scaled back recently, because of the bad publicity they received due to their risk algorithms repeatedly punishing perfectly good customers.
The main difference between AmEx and Chase is that AmEx's adverse action were targeted more individually based on a long list of sometimes bizarre risk triggers, while Chase's actions are aimed at an entire group of accounts. In the case of the ex-WaMu accounts, Chase acquired that portfolio as a side effect of gaining the WaMu banking presence in the West, which was its primary interest. They probably always knew they would need to lop off the worst accounts in the CC portfolio, hence the current CLD/closure action affecting 15% of the ex-WaMu accounts. Aside from ex-WaMu accounts, Chase's actions have affected a very small percentage of their customer (the combined January and August minimum payment increase to 5% affected less than 1% of their accounts).
Both AmEx and Chase are in the process of reducing overall credit limits by about 30% by mid-2010 to strengthen their balance sheets. And AmEx saw double-digit default rates earlier this year. I wouldn't say AmEx had too much to brag about ... 
