Theft Prevention Innovations LLC (TPI), a newly formed affiliate of Empire IP LLC, has filed three complaints against four location tracking companies, AwarePoint (2:16-cv-00469), AiRISTA and Ekahau (2:16-cv-00470), and Sonitor Technologies (2:16-cv-00472). The May 3 complaints each assert two patents (7,671,741; 9,165,446) from a family of three that generally relate to a security system based on attachable security tags, each of which has an alarm that sounds when the tag is removed or moved into a predetermined “warning zone”. Defendants are accused of infringement through the sale of real-time location systems (RTLS) that use RFID or ultrasonic security tags.