The riot, on the morning of June 3, had its roots in the refusal of China’s government to permit the establishment of any independent organization, including nongovernment labor unions, as a reliable, independent channel for workers’ grievances. It was a shocking first for Xizhou, a raw industrial zone on the northeastern edge of the city of Guangzhou, in southern China’s muggy Pearl River Delta. But across China there are thousands of such explosions every year — by farmers who lose their land, workers who get laid off and villagers who feel cheated by corrupt officials.