U.S. Trade Rep Calls Chinese Filtering Complex

China's comprehensive Internet filtering regime for political, social or religious content is complex and opaque -- creating precarious conditions for providers, the U.S. Trade Representative's official said in its annual report to the U.S. Congress. In a report compiled before Google Corp. moved its Chinese search portal to Hong Kong from China this month in a censorship dispute, the USTR said: "changes to Internet filtering can occur without warning or public explanation."