China's workforce is growing more restive as it shrinks…The number of strikes so far this year is up by close to a third…Employers face an uncomfortable new reality: workers who not only know their rights and will challenge management to defend them, but who also demand more than the legal minimum…Thousands of workers at a factory…run by Yue Yuen Industrial Holdings…have been on strike for around 10 days demanding improved social insurance payments, a pay rise and more equitable contracts…Other companies caught up in this rising tide…so far include Wal-Mart Stores Inc,…International Business Machines Corp (IBM),…Lenovo Group Ltd,…and Samsung SDI Co Ltd, whose supplier [is] Shanmukang Technology…China's working age population shrank by almost 6 million in the past two years…and by government policies to better protect worker interests after decades of neglect…China has overhauled its labour legislation in recent years…