As China approaches the 25th anniversary of the Tiananmen Square crackdown, the Communist Party is taking no chances with dissent, online or off.

Google services including search, Gmail and Translate have been disrupted since at least late last week, according to Greatfire.org, a site that tracks internet access. Police detained dozens of people and warned foreign journalists against writing stories about the June 4, 1989, crackdown, and The Wall Street Journal's website was blocked.

The Tiananmen anniversary poses the biggest challenge yet to efforts by President Xi Jinping to police dissent more actively in a nation with 618 million web users. Tighter controls reflect a strategic shift toward using the internet to shape public opinion and curtail unrest while also championing the emergence of a homegrown technology industry led by Tencent Holdings and Alibaba Group Holding.

"The previous regime took more of a reactive approach toward internet regulation, but the new government sees the internet as a larger threat, so a lot of what they do is preemptive," said Beijing-based activist Zhao Jing, who writes about internet and press freedom under the name Michael Anti. "This regime wants to fully utilize Internet monitoring methods and big data mining to nip potential hazards for social instability in the bud."

Managing content
China's leaders have long managed internet content, blocking pornography, dissident websites and any other information it deems a threat. Facebook and Twitter are inaccessible. Discussion has always been limited concerning the Tiananmen crackdown, in which leader Deng Xiaoping sent troops to break up student-led protests in the square at the heart of Beijing. No independently verified death toll exists but hundreds are believed to have been killed.

In the lead-up to this year's anniversary, at least 50 people in China have been detained, summoned by the police for questioning, or have disappeared, overseas monitoring group Chinese Human Rights Defenders said in a May 29 e-mail. Five activists were detained by police after attending a May 3 commemoration of June 4th, according to the group.

Some foreign media correspondents and their local staff also have been summoned and given videotaped lectures seeking to dissuade them from reporting on the anniversary, the Foreign Correspondents' Club of China said in a June 2 e-mail statement.

Attempts to access Google's main search page in China through the Chrome browser on Tuesday brought up a notice that said the web page wasn't available. Google's Images and Translation pages also were blocked, as was Gmail.

Severely blocked
"In an effort to prevent the dissemination of information related to this event, the Chinese censorship authorities have severely blocked most Google services in China, including search and Gmail," Greatfire said in a June 2 e-mail.

Google's Transparency Report page shows China making up a smaller percentage of global traffic in the past few days, compared with earlier periods. The company has "checked extensively and there are no technical problems on our side," Google said in an e-mailed statement about its China services.

Google has long wrestled with the best approach to China's internet controls. In 2010, Google said it wouldn't self-censor content for Chinese services, shut its local search page and directed users to its Hong Kong website. For a time in 2012 and 2013, it notified users in China if their search terms might become targets of censors and result in disruptions.

LinkedIn controls
It isn't the only firm to grapple with the issue. LinkedIn spokesman Roger Pua said in an e-mail today that "censorship requirements" had recently been imposed on the company's China service. LinkedIn understands it needs to implement Chinese content restrictions to "create value for our members in China and around the world," Pua wrote.

China regulates cyberspace in accordance with the law, Foreign Ministry spokesman Hong Lei said at a briefing today. Asked about the Tiananmen crackdown, he said China's position is clear.

"In more than 30 years of reform and opening up we have achieved remarkable progress," he said. "These realities show that the path we've chosen is in line with our national conditions and the fundamental interests of the Chinese people."

Xi telegraphed his interest in the internet when he visited the headquarters of Tencent, China's largest internet company, during his first trip outside Beijing after becoming general secretary of the ruling Communist Party in 2012. He told staff the data gathered by Tencent is a valuable government tool. The Web plays "a big role in managing society," he said.

Jailed
In September, China's supreme court ruled that authorities could jail web users for as long as three years if they post comments deemed defamatory. The new policies are starting to have a chilling effect on public discourse.

Pu Zhiqiang, a civil rights lawyer, said when the defamation laws were rolled out that authorities in the future could selectively use the rules as a tool to punish people.

"This can't last long," Mr. Pu said in an interview at the time. "If you do arrest all the people spreading rumors, would you have a big enough jail to hold up all of them?"

Mr. Pu, who took part in the Tiananmen protests in 1989, was detained May 4, a day after attending the commemoration of the crackdown. He hasn't been seen in public since.

~ Bloomberg News ~