Green Dam definitively blocks political sites - and creates security breach

According to The Wall Street Journal, a report by Harvard University researcher Isaac Mao, who has seen the code, says Green Dam's data files block "much more than Falun Gong."

Mr. Mao, who has seen the program's coding, said the words in the lists aren't necessarily blocked by the software. He said the blocking will appear inconsistent to users because the program includes mechanisms that activate and deactivate various functions. The software also appears to communicate with a centralized server, he said.

The report follows revelations by Chinese blogger Shi Zhao that the data files refer to "6-4 massacre" -- a reference to the Tiananmen Square crackdown on June 4, 1989 -- and "the celebration of Tibetan people." According to Shi:

There are two kinds of keyword documents in the software: one is related to pornographic content, and the other related to political content. The documents related to political stuff are very big -- much, much bigger than those related to pornographic content.

Bryan Zhang, founder of Green Dam developer Jinhui, denies these allegations. "I know what it is on my own blacklist," he said.

And - coincidentally - the software contains programming errors that create "serious vulnerabilities that allow any Web site the user visits to take control of the PC," according to a University of Michigan study.