Specifically, webcaster Intercollegiate Broadcasting System (IBS) challenged the legitimacy of the CRB structure and authority, as the process for appointing the judges comprising the board violated the Appointments Clause of the U.S. Constitution. The authorizing statute called for the board's three permanent copyright royalty judges to be appointed by the Librarian of Congress. IBS argued in its appeal that since the judges "exercise significant authority with limited supervision" they qualified as "principal officers" which the Appointment Clause says must be appointed by the President with Senate confirmation. The appeals court panel agreed -
"Billions of dollars and the fates of entire industries can ride on the Copyright Royalty Board's decisions," Senior Circuit Judge Stephen Williams wrote for panel.Rather than nullifying the whole CRB structure and opening its previous actions to challenge, the panel struck down the section of the authorizing statute that said that the Librarian of Congress could only remove the CRB judges "for cause." That would allow the appointed judges to be considered "inferior officers" rather than "principal officers," and thus for the CRB to be considered constitutional - at least going forward. This still leaves previous CRB actions in doubt, but at least allows future decisions and actions to be considered as constitutional.
Source - Appeals court rejects Copyright Royalty Board structure, redefines judges' roles, Fierce Online Video