I have been credit crunched!

It says subject to applicable law, therefore if any of the terms are unfair they are invalid.

Basically they can put what they like, if I think their terms are unfair and a court agrees with me I'm free to ignore their terms.

I have had a victory using this act before actually.

"We may change the terms of, or add new terms to, the Cardmember Agreement at any time, subject to applicable law. We may apply any changed or new terms to any existing and future balances on your Account, subject to applicable law."

taken direct from from Amex T&Cs on their site.