https://arstechnica.com/tech-policy/2018/04/supreme-court-upholds-important-weapon-in-the-fight-against-bad-patents/ [arstechnica.com]
"Congress can grant a franchise that permits a company to erect a toll bridge but qualify the grant by reserving its authority to revoke or amend the franchise," the court's majority wrote, citing a 101-year-old precedent on the topic. "The same is true for franchises that permit companies to build railroads or telegraph lines."