American Express sued Visa and Mastercard in 2004: http://www.nbcnews.com/id/6494456/ns/business-us_business/t/...

They settled in 2007 : http://www.nytimes.com/2008/06/26/business/26credit.html

Mastercard paid $1.8 billion, Visa paid $2.1 billion

MA and V have way outperformed AXP since.