Network Monitoring LLC has filed its first litigation, suing Booking Holdings subsidiaries Agoda (2:21-cv-00145), Booking.com (2:21-cv-00146), and Momondo (2:21-cv-00147) in separate suits, as well as Expedia (Trivago) (2:21-cv-00150) and Trip.com (SkyScanner) (2:21-cv-00148), all in the Eastern District of Texas. The two asserted patents generally relate to monitoring a user’s online activity by embedding, within a URL, an address corresponding to a tracking system. The defendants are accused of infringement through the provision of their respective travel websites, with features for monetizing the use of their services through referral links at issue.