Summary Labour conflicts in Chinese factories hit 7-year high-CLB Chinese manufacturers hit by weak global demand Economists and activists expect more frequent strikes Factory protests could become 'source of instability'-economist BEIJING, June 15 (Reuters) - Strikes at Chinese factories have surged to a seven-year high and are expected to become more frequent as weak global demand forces exporters to cut workers' pay and shut down plants, one rights group and economists say. Exports and factory output in the world's second-largest economy tumbled in May, as looming downturns force the United States and Europe to pare back orders for goods made...