The 9th Circuit Court of Appeals upheld the lower court ruling, saying that the plaintiffs have failed to show that the law, known as AB 5, unfairly singled out app-based transportation companies. A U.S. appeals court struck down a bid by Uber and its subsidiary, Postmates, on Monday that tried to reignite a challenge to a California law that could force certain companies to treat gig workers as employees rather than independent contractors.