Police in China's capital said Tuesday they will start patrolling the Web using animated beat officers that pop up on a user's browser and walk, bike or drive across the screen warning them to stay away from illegal Internet content. Starting September 1, the cartoon alerts will appear every half hour on 13 of China's top portals, including Sohu and Sina, and by the end of the year will appear on all Web sites registered with Beijing servers, the Beijing Public Security Ministry said in a statement. China stringently polices the Internet for material and content that the ruling Communist Party finds politically or morally threatening. Despite the controls, nudity, profanity, illegal gambling and pirated music, books and film have proliferated on Chinese Internet servers. The animated police appeared designed to startle Web surfers and remind them that authorities closely monitor Web activity. However, the statement did not say whether there were plans to boost monitoring further.