RPX reported two weeks ago that inventor Alan Loudermilk had joined Caddo Systems, Inc. as a director, in possible preparation to assert the patents of Armin Moehrle. Loudermilk is also one of two named directors for 511 Innovations, Inc., an entity actively engaged in the enforcement of Loudermilk patents, most recently against Apple. Indeed, Caddo Systems and 511 Technologies, Inc.—another entity controlled by Loudermilk—have now teamed up to assert five of those Moehrle patents (7,191,411; 7,216,301; 7,640,517; 7,725,836; 8,352,880), suing Delta Airlines (2:16-cv-00925), Internet Brands(2:16-cv-00927), Southwest Airlines (2:16-cv-00926), and Tencent (Zam Network) (2:16-cv-00928) in the Eastern District of Texas. The defendants’ website navigation systems are accused of infringement.