Before agreeing to buy mobile messaging startup WhatsApp for an eye-popping $19 billion, Facebook Inc. likely eyed two patent cases pending in Delaware and Bay Area federal courts.

TriPlay Inc., represented by Greenberg Traurig, accuses WhatsApp of violating patented technology for communicating between devices where the message format from the sender is converted to facilitate delivery to the recipient.

According to a complaint filed in October in U.S. District Court in Delaware, TriPlay was founded in 2004 for the purpose of developing content delivery technology that allows users to communicate across devices regardless of its manufacturer. Its research and development resulted in the issuance of patent no. 8,332,475.

TriPlay alleges that WhatsApp violates claims 1 and 12 of its ‘475 patent. WhatsApp has not yet responded to the complaint.

In the Northern District of California, WhatsApp filed last year for a declaratory judgment against Intercarrier Communications, an arm of Acacia Research Group. WhatsApp is represented by Latham & Watkins, and ICC has tapped Jonathan Baker of Farney Daniels.

ICC is alleging infringement of patent nos. 6,985,478 and 8,483,729, which cover intercarrier messaging services using only phone numbers. WhatsApp argues the ICC patents are abstract, obvious in relation to prior art, and lack utility. U.S. District Judge Jon Tigar has scheduled a claims construction hearing for September.