Apple has been ordered by a federal court in Texas today to pay $502.6 million to a patent troll called VirnetX, the latest turn in an eight-year-old legal battle over FaceTime and iMessage patents, according to Bloomberg.

Apple and VirnetX have been fighting in court since 2010, when the patent-holding company said the iPhone maker infringed on four of its patents related to internet-based communications. The legal battle has been protracted, and it involves multiple lawsuits and a dizzying number of appeals. Last we heard of the fight was in October 2017, when Apple was ordered to pay $439.7 million, a ruling the company then appealed.

VirnetX is a patent-assertion entity, meaning its entire business model rests solely on suing companies that actually develop and sell products based on arcane patent infringement laws and loose interpretations of intellectual property regulations. VirnetX is based in Zephyr Cove, Nevada, and it filed its suit in patent troll-friendly East Texas, a district where patent holders have had a higher chance of success in intellectual property cases until the Supreme Court cracked down on the practice last year.

VirnetX, in a SEC filing, described its approach to making money by saying its “portfolio of intellectual property is the foundation of our business model.” The company’s stock rose 44 percent today on news of the federal ruling in its favor, Bloomberg says. However, the ruling may eventually be struck down. The US Court of Appeals for the Federal Circuit in Washington is currently reviewing cases in which the Patent Trial and Appeal Board claims the patents in question are in fact invalid.