BEIJING (Reuters) - Twenty-five years ago, Wang Nan took his camera and headed out to Beijing's Tiananmen Square, where tens of thousands of people had gathered calling for democratic reforms. The 19-year-old told a friend he wanted to record history.
Before he left his home late on June 3, 1989, he asked his mother："Do you think the troops would open fire?" She said she did not. Around three hours later, he was shot dead by soldiers.
As his 77-year-old mother, Zhang Xianling, prepares to mark the 25th anniversary of her son's death, she is under around-the-clock surveillance by eight police and security officers.
Zhang said the level of scrutiny this year was unprecedented. As early as April, police officers barred foreign journalists, including Reuters reporters, from visiting her home.
"I find it ridiculous, I'm an old lady," Zhang told Reuters by telephone. "What can I say (to reporters)? I don't know any state secrets. All I can talk about is the matter concerning my son. What is there to be afraid of?"
The Chinese Communist Party's harshest crackdown on political dissent in recent years would suggest plenty.
As Wednesday's big anniversary of the bloody repression of pro-democracy protests in Tiananmen Square approached, authorities deployed hundreds of police, many armed with rifles, to patrol the area.
Rights group Amnesty International said at least 66 people have been detained in connection with the anniversary, and major Chinese internet sites censor references to the day on which hundreds, possibly thousands of unarmed civilians were killed.
For Zhang, whenever she wants to travel anywhere she is driven in a police car. Two police officers walk with her when she goes to the market.
In previous years, Zhang said she was usually guarded by three to five police officers who would appear outside her home a month before the anniversary.
The extraordinary measures are explained by the fact that she is one of the co-founders of a group of families called the Tiananmen Mothers, who have long demanded justice for the victims of the massacre.
Ding Zilin, the other co-founder who was travelling in the eastern city of Wuxi, near Shanghai, was not allowed to return to Beijing, said Zhang and other rights activists.
"There is much empathy for them given they lost children in 1989," said William Nee, Amnesty International's China researcher. "They are seen as credible and their continued fight for justice, especially given their age, has drawn much sympathy.
"The authorities are acutely aware of this and that is why we believe they are placed under such heavy surveillance this year."
Asked about the restrictions on the Tiananmen Mothers, China's Foreign Ministry spokesman Hong Lei said the legal rights of Chinese citizens are guaranteed, but every Chinese citizen must "consciously respect the country's rules and laws".
Since Xi Jinping became president in March last year, his administration has taken a hard line on dissent, detaining and jailing activists, clamping down on Internet critics and tightening curbs on journalists in what rights groups call the worst suppression of free expression for several years.
Censors have scrubbed out references on Weibo, China's version of Twitter, to 'May 35th', a substitute for the date of the Tiananmen crackdown.
Tencent Holdings Ltd's microblog censors the characters for 'willow silk', which sound similar to the words 'six four', a Chinese way to say June 4.
Qihoo 360 Technology Co censors 'VIIIIXVIIV', the Roman numerals for '8 9 6 4' or June 4, 1989.
"The government is concerned about what they call stability maintenance," said Andrew Nathan, a professor of political science who specialises in Chinese politics at Columbia University in New York.
Nathan said Chinese leaders are concerned about the so-called "Arab Spring" uprisings and revolutions in Ukraine, and want to prevent such open acts of rebellion against the state from taking hold in China.
"So their idea of preventing it is not to take the lid off and let people hash things out, but instead try to prevent anybody from raising any of these troubling issues," he said.
After initially tolerating the student-led demonstrations in the spring of 1989, the Communist Party sent in troops to crush a rare display of public defiance.
The government has never released a death toll from the violence, but estimates from human rights groups and witnesses range from several hundred to several thousand.
Stunned by the government's harsh response to the Tiananmen movement that officials have termed "counter-revolutionary", and tired of decades of turmoil under Communist rule, many Chinese people now balk at the idea of mass revolution.
Instead, they chase new opportunities offered by the country's booming economic growth.
And while the authorities have moved swiftly to squash criticism of the one-party system, people are enjoying the kind of individual freedoms never accorded them before.
They can report on corrupt officials, sue the government for pollution and miscarriages of justice, and stage protests for labour and environmental rights.
The Chinese government has also loosened the one-child policy, allowing many urban couples to have two children.
It has been effective, too, in scrubbing out memories of the 1989 protests. Many young people, indoctrinated by years of "patriotic education", have no inkling of the movement.
Beijing has forced many of the student leaders into exile in the United States, Hong Kong and Taiwan, where they are effectively neutralised, being barred from the mainland.
"Once we leave China, we've left the battlefield," said Wu'er Kaixi, a leading figure in the pro-democracy movement who now lives in Taiwan. "We are no longer the main actors on the stage."
Wang Dan, who was one of the most visible leaders in the movement and is also in exile in Taiwan, said he was able to hold a "democracy salon" - an open forum for intellectuals to discuss political problems - at Peking University 25 years ago.
"Everyone knows that anyone who dares to do anything like that these days will be detained. This is a clear regression from where we were back then."
Additional reporting by Michael Gold in TAIPEI and Ben Blanchard and Paul Carsten in BEIJING and Reuters Television in NEW YORK; Editing by Mike Collett-White