In "Princo Corp. v. International Trade Commission", the Federal Circuit held that violations of antitrust law involving patents are not always patent misuse. Philips, Sony and other manufacturers developed patented technology to create CDs that could be rewritten multiple times (CD-RWs). Philips licensed these patents to CD player and reader manufacturers (so they could develop CD players and readers that worked with CD-RWs). Princo Corp., one of the licensees, stopped paying royalty fees to Philips, but continued to manufacture readable discs using Phillips technology. Phillips filed a complaint with the International Trade Commission and Princo responded claiming that Sony and Phillips were using their patents to suppress competition. On appeal, an en banc the Federal Circuit Court of Appeals held that Sony and Phillips had not expanded the scope of their patent in a way prohibited by previous Supreme Court cases. Namely, the violation allegedly did not "leverage" the patent at hand. According to one commentator, patent scholars have speculated that this opinion will significantly narrow the scope of misuse.