The Norris–La Guardia Act of 1932 prohibits employers from proscribing the peaceful dissemination of information concerning the terms and conditions of employment by those involved in an active labor dispute, even when such dissemination occurs on an employer's private property. Decided March 28, 1938 (argued 1938). Opinion of the Court: Owen Roberts → go there Dissenting: McReynolds. Topic: Federalism. New Negro Alliance v. Sanitary Grocery Co., 303 U.S. 552 (1938), was a landmark decision of the US Supreme Court which affects US labor law, safeguarding a right to boycott and in the struggle by African Americans against discriminatory hiring practices. Sanitary Grocery Co. was at the time of the case owned by Safeway Inc. Wiki link