Employees at the world’s biggest Apple iPhone factory have been beaten and detained in protests over contract disputes amid anti-virus controls, according to employees and videos posted on social media Wednesday. Videos on Chinese social media that said they were filmed at the factory in the central city of Zhengzhou showed thousands of people in masks facing rows of police in white protective suits with plastic riot shields. One person was hit in the head with a club and another was taken away with his arms held behind his back. Postings on social media said they were protesting unspecified contract...