On March 21, 2017, U.S. Court of Appeals for the Ninth Circuit overturned a trial court decision that would have legitimized a business model based on the unauthorized, for-profit exploitation (via the Internet) of the copyrighted works of others. The decision proved a victory for Washington Legal Foundation, which filed an amicus curiae brief in the case arguing that the district court misapplied federal copyright law by drastically expanding the definition of “cable system” under § 111 of the Copyright Act. Writing for a unanimous panel, Judge O’Scannlain concluded that § 111 is ambiguous on the question presented. Deferring to the Copyright Office’s interpretation—which WLF’s brief urged the court to do—the appeals court held that Internet-based retransmission services are not eligible for the compulsory license that § 111 makes available to “cable systems.”