Virtual Fleet Management, LLC (VFM) has filed affirmative infringement cases against Fleetilla (2:16-cv-00646) and US Fleet Tracking (2:16-cv-00647) in the Eastern District of Texas. The two defendants had each filed an earlier action seeking declaratory judgments of non-infringement and invalidity of a single patent (6,958,701), Fleetilla in March in Michigan (2:16-cv-11060) and US Fleet Tracking in April in Oklahoma (5:16-cv-00376). The ‘701 patent generally relates to detecting the approach of a specific vehicle or tracker, and the defendants are accused of infringement through provision of fleet tracking services.