Social Positioning Input Systems, LLC (SPIS), one of many NPEs controlled by prolific inventor Leigh M. Rothschild, has sued ClearPathGPS (2:21-cv-00519) in the Central District of California, Lytx (3:21-cv-00104) in the Southern District of California, and Particle Industries (3:21-cv-00464) in the Northern District of California. The sole patent-in-suit generally relates to transmitting the location information of a positional device, with the defendants accused of infringement through the provision of vehicle fleet tracking systems. Rothschild ended last year near the top of the list of frequent NPE plaintiffs, second only to Texas monetization firm IP Edge LLC.