Collectives encouraged autarky and self-sufficiency, refusing to share with other collectives. Communes, collectives, and intentional communities regained popularity during this era. The Nivkh were forced into mass agricultural and industrial labour collectives called "kolkhoz". Many anarchist collectives contain the word "black" in their names. Socialists aimed to reclaim the land by becoming peasants or workers and forming collectives. In some countries PROs are called copyright collectives or copyright collecting agencies. Women were often highly involved with their local agricultural collectives during the war. Even those collectives that had been created voluntarily were raided. Stalin barred kulaks from joining these collectives. Thacker has also collaborated with art, media, and music collectives. A number of Zionist agricultural collectives were established in Crimea in preparation for Kibbutz life. The Weather Underground hoped to create underground collectives in major cities throughout the country. Arts & Culture manages a number of extra-curricular arts collectives. The second was to create underground collectives in major cities throughout the country. Households were encouraged to sign contracts with economic collectives.