From the AP, via the Columbia Daily Tribune:
Farmers had long feared the runoff from the pharmaceutical factory. It turned irrigation water to a greasy, red sludge and stunted vegetable crops. They blamed it for a local rise in cancer and birth defects.
When a drought concentrated pollutants such as never before, they turned to action, attacking the Jingxin Pharmaceutical Co. plant with rocks and farm tools and forcing it to suspend production.
Such scenes of frustration are occurring with increasing frequency across rural China as villagers rise up against corruption, pollution and the seizure of land for real estate development. With little faith in local officials or the weak legal system, violence often is considered the only way to air their grievances.