Beijing’s top legislative body has unanimously passed a controversial and wide-reaching national security law for Hong Kong, which critics fear could be used to repress free speech after mass pro-democracy protests swept across the region last year. The standing committee of the National People’s Congress approved the measure Tuesday morning, and President Xi Jinping signed an order promulgating the law a short time later, the official Xinhua News Agency confirmed. “We hope the law will serve as a deterrent to prevent people from stirring up trouble,” said Tam Yiu-Chung, Hong Kong’s sole representative on the Standing Committee.