Joint brief of the United States and the Federal Trade Commission as amicus curiae supporting petitioner, and urging reversal of a decision of the United States Court of Appeals for the Sixth Circuit. That court held that the bona fide error defense of the Fair Debt Collection Practices Act (FDCPA), 15 U.S.C. § 1692k(c), could apply not just to clerical or mathematical errors, but also to errors of law. The brief argues that errors of law do not satisfy the FDCPA’s requirements for a “bona fide error” because such errors are never “not intentional,” and because a debt collector cannot maintain procedures reasonably adapted to avoid errors of law. The brief also argues that the provision was based on an identical provision in the Truth in Lending Act, which excludes errors of law.