A look at dissidents who have left China

Chinese dissidents know their influence can fade after they leave the country, and they face the possibility of never coming home, even to visit family or attend funerals.

The issue came up after blind legal activist Chen Guangcheng escaped house arrest and fled to the U.S. Embassy. Friends at first said he didn't want to leave the country, but now Chen says he wants to leave China for the safety of him and his family.

Some dissidents in exile plead with the Chinese government for a chance to even briefly return. In an open appeal last month, six exiles who participated in the Tiananmen Square pro-democracy uprising in 1989 again asked for permission to visit. "We believe that returning to one's motherland is an inalienable right of a citizen," Wang Dan and the others wrote.

Some activists believe they can do more to defend human rights by staying in China. But waves of abuse from authorities have driven several high-profile activists out of China over the years. Here are some of them.

FANG LIZHI: China's leading astrophysicist sought refuge at the U.S. Embassy after China's 1989 crackdown on pro-democracy demonstrations at Tiananmen Square. Authorities said Fang's speeches helped incite the protests, and he and his wife were named in warrants that could have carried death sentences upon conviction. The two stayed at the U.S. Embassy for 13 months while China and the U.S. discussed them. China allowed them to leave in 1990. Fang died last month in the United States at age 76 after teaching at the University of Arizona.

WEI JINGSHENG: The democracy activist was a soldier and electrician whose faith in China's communist order was shaken by Mao Zedong's ruinous policies. Wei spent a total of 17 years in prison for urging reforms. He was released in 1993 as China pursued the chance to host the 2000 Summer Olympics, but he was arrested again after Beijing's bid failed. The U.S. negotiated his release in 1997, and Wei was granted a medical parole. He lives in Washington.

REBIYA KADEER: Kadeer was once considered a success in modern China: an ethnic Uighur from the troubled far western region of Xinjiang who became a millionaire entrepreneur with a prestigious government advisory post. But she was arrested in 1999 and sentenced to eight years in prison for mailing newspaper reports of anti-Chinese unrest to her husband overseas and for trying to give a list of political prisoners to U.S. congressional staff. She was released in 2005, shortly before a visit to China by then-U.S. Secretary of State Condoleezza Rice. Kadeer now lives in the U.S.

WANG DAN: Wang was on China's list of most wanted student leaders after he helped lead the 1989 pro-democracy demonstrations at Tiananmen Square in Beijing. Wang also was released from prison in 1993 as China pursued the chance to host the 2000 Summer Olympics and detained once more when the bid fell through. He was released on medical parole and left for the U.S. in April 1998. Wang graduated from Harvard University with a doctorate in history in 2008 and moved to Taiwan.

WU'ER KAIXI: Wu'er was also on China's list of most wanted student leaders for the Tiananmen Square demonstrations. Wearing pajamas, the young hunger striker drew attention when he harangued then-Premier Li Peng during a televised meeting with protesters. Wu'er fled China with the help of a secret network that helped numerous Tiananmen protesters leave the country through Hong Kong and Macao. He lives in Taiwan, where he is a businessman and political commentator. He made headlines in June 2010 when police in Japan arrested him for allegedly trying to force his way into the Chinese Embassy in Tokyo on the anniversary of the Tiananmen crackdown.

LIAO YIWU: The writer and former political prisoner fled to Germany last July after a secretive journey with stops in Vietnam and Poland. Authorities had been especially harsh on his previous efforts to leave China for literary festivals and other events, blocking him from traveling overseas more than a dozen times. Before he fled, he said police had warned him several times that if he published anything overseas again, he would be jailed. He is known for "The Corpse Walker," a published series of interviews with people on the margins of China's society.

WAN YANHAI: Wan founded a prominent AIDS advocacy group in China but fled to the U.S. in 2010, leaving during a business trip to Hong Kong with his wife and child. Tighter regulations on overseas donations to Chinese aid groups had hurt his work, and he said he received dozens of phone calls from police in a single day shortly before he fled. In the past, the former Health Ministry official had been detained for up to weeks at a time for advocacy work that included publicizing an AIDS scandal among poor villagers in the 1990s.

YU JIE: Yu wrote a book critical of the premier called "China's Best Actor: Wen Jiabao" and helped found the Independent PEN Center in China, which fights for freedom of expression. He left in January for the U.S. after being detained several times last year and being beaten so badly that he passed out. Yu has said he doesn't plan to return to China for a few years, but he thinks authorities won't let him return because he accused them of torture. When he left China, the Global Times newspaper taunted him with a commentary headlined, "Self-imposed exile reflects one's waning influence."