Purple Leaf filed suit against Zuora, an enterprise software company that offers cloud-based billing and payment subscriptions. Since May 2011, Purple Leaf has filed four prior suits against 10 companies, including Amazon, American Express, Citigroup, eBay, Fiserv, Google, JP Morgan, Paypal, PNC Bank, and SAP, alleging that the defendants’ receipt-based payment systems infringe a patent related to conducting electronic payment transactions over the Internet (7,603,311).  Rani Yadav-Ranjan is the named inventor of the patent asserted in the prior suits, which was assigned to Purple Leaf in April 2010. The complaint in the current suit is currently not available. 1/22, Northern District of California, assigned to Judge Laurel Beeler, 3:2013cv00299.