Chinese leader Xi Jinping has built a sprawling security system to prevent violent forces from destabilizing society. A new wave of deadly attacks is putting pressure on officials to expand that surveillance state. China was stunned this month by its deadliest act of public violence since a string of terrorism strikes rocked the remote Xinjiang region in 2014. Dozens were hospitalized and 35 killed by the bloody car-ramming in Zhuhai city that was the culmination of a spate of violence this year -- mostly stabbings -- which have sparked nationwide anxiety. Xi responded to spouts of ethnic violence a decade ago by installing a network of facial recognition cameras, tightening Internet controls and expanding a national resident database.