Hong Kong pro-democracy campaigner Martin Lee, center, shouts slogans with fellows during a march to the government office in Hong Kong Sunday, May 31, 2009 to mark the 20th anniversary of the military crackdown on a pro-democracy student movement in Beijing. Large throngs of Hong Kong march on Sunday in protest of China's suppression of pro-democracy protesters at Beijing's Tiananmen Square 20 years ago, in one of the few public commemorations of the crackdown on Chinese soil. AP Photo logo AP Photo 6 months ago

Hong Kong pro-democracy campaigner Martin Lee, center, shouts slogans with fellows during a march to the government office in Hong Kong Sunday, May 31, 2009 to mark the 20th anniversary of the military crackdown on a pro-democracy student movement in Beijing. Large throngs of Hong Kong march on Sunday in protest of China's suppression of pro-democracy protesters at Beijing's Tiananmen Square 20 years ago, in one of the few public commemorations of the crackdown on Chinese soil.