The debate over requiring greater disclosure of the funding sources for amicus briefs was itself at the center of a friend-of-the-court brief filed this week in the U.S. Court of Appeals for the Ninth Circuit, as part of Google’s appeal over Google Play platform changes.

University of Masssachusetts Amherst political science professor Paul Collins Jr. wrote that public records show numerous amici supporting Google in the underlying antitrust case have had financial ties to the company. He urged the panel to view those filings with skepticism.