The AP story below indicates that the Dept. of Justice is looking into Amex's fight against merchants trying to get customers to use other, (cheaper) cards. Since Amex's higher charges are the prime source of its (somewhat) better rewards programs, this could have a bad effect on Starpoints, Membership Rewards, et al. (although perhaps an overall positive effect by lowering credit card charges).

"American Express said it intends to cooperate with the department's [of Justice] request for documents and other information regarding the company's policies related to merchant surcharging and its "anti-steering" policies that prohibit merchants from discriminating against the American Express card in favor of other forms of payment."

Entire story at:
http://news.yahoo.com/s/ap/20081031/...nvestigation_1