The trustee in bankruptcy in this case is seeking to obtain certain accounts receivable of the bankrupt which had been assigned to Aetna Factors Co. in violation of express terms of the contracts under which the accounts arose. The Bankruptcy Act empowers the trustee to reach any asset which an ideal lien creditor of the bankrupt could reach. 11 U.S.C.A. § 110, sub. c. The rights and powers of such a creditor are determined by state law. Under California law, the state in which the transaction occurred, a creditor would be unable to defeat the assignment. Johnston v. Landucci, 21 Cal.2d 63, 130 P.2d 405, 148 A.L.R. 1355. The judgment of the District Court holding that the trustee could not reach the accounts is affirmed.