I am dismayed that Prof. Singer left out Mao Zedong, China's late dictator and mass murderer. Mao was responsible for the deaths of more than 40 million Chinese and is considered the most brutal and blood-thirsty tyrant in Chinese history. Tallying up the deaths caused by his personal instructions and policies may be a challenge for Prof. Singer, but it is doable. In the early 1950s, shortly after Mao's regime gained power, Mao set an arbitrary target that one out of each thousand people must be shot because that was his ratio of counter-revolutionaries to ordinary people. Of course, when carried out, his zealous underlings killed far more people (this directive alone led to the deaths of more than 1 million people). In 1957, he launched a purge of the intelligentsia, sending half a million people to the prison camps. Tens of thousands never returned. Of course, Mao's greatest crime was committed during the Great Leap Forward famine. At least 36 million starved to death. During the Cultural Revolution, at least 3-4 million people were murdered. The trauma Mao's regime inflicted on Chinese society was deep and enduring. Even today, most Chinese who have lived through his reign of terror have a hard time bringing themselves to talking about those days. But Mao seems to have got away with mass murder. His body has been preserved and is on view for tourists in Beijing. His picture still hangs on Tiananmen. The Chinese Communist Party has revived some of his political rhetoric and is eager to preserve his image as a strong leader because the party is aware that classifying Mao as a criminal comparable to Stalin or Hitler would destroy its legitimacy. Last month, the party even staged a lavish ceremony commemorating the 120th birthday of the late dictator. I wish Prof. Singer had thought about Mao when commenting on who should get the title of History's Worst Mass Murderer.