A Chinese official in charge of regulating the Internet has said Beijing must strengthen Internet security because overseas hostile forces are using the Internet to attack, slander and spread rumors, state media said on Sunday. Wang Xiujun, the deputy director of the China National Internet Information Office, said political security is fundamental, reported The Peoples Daily, the official newspaper of the ruling Chinese Communist Party. Wangs remarks coincide with a broad crackdown on online freedom of expression that has intensified since President Xi Jinping came to power last year. Now, overseas hostile forces are using the Internet as a main channel to penetrate and destroy (us), Wang was quoted as saying.