Purple Leaf [NPE] filed suit against SAP, American Express, Citgroup, Fiserv, JP Morgan Chase, and PNC Bank for alleged infringement of patent related to electronic payment transactions. 5/31, Eastern District of Texas, 6:2011cv00279.  This is the first patent suit filed by Purple Leaf.  Purple Leaf appears to be an entity controlled by the individual inventor of the patent-in-suit. The patent has a 1999 priority and was directed to Internet based payment of parking tickets.