Paramilitary policemen and security officers stand guard next to members of the public in front of the giant portrait of Chairman Mao Zedong on Beijing's Tiananmen Square June 3, 2009. Chinese security forces blanketed Tiananmen Square on Wednesday ahead of the 20th anniversary of the June 4 crackdown on pro-democracy protesters, a day after Twitter and Hotmail Internet services in China were blocked. REUTERS/David Gray (CHINA)