BEIJING — Thirty years ago, China sent its first-ever email.
"Across the Great Wall, we can reach every corner of the world," the Mail Administration of China wrote to researchers at Germany's University of Karlsruhe at 9:07 p.m. Beijing time on Sept. 14, 1987.
But instead of bridging the wall, China has since built a new one, in cyberspace — the largest system of Internet censorship, control and surveillance in the world, nicknamed the Great Firewall of China.
Thirty years on, it is extending those controls even further.
Since passing its broad new Cybersecurity Law in June, the Communist Party has rolled out new regulations — and steps to enforce existing ones — that reflect its desire to control and exploit every inch of the digital world, experts say.
Today, the Great Firewall is being built not just around the country, to keep foreign ideas and uncomfortable truths out, but around every individual, computer and smartphone, in a society that has become the most digitally connected in the world.
Last month, the Cyberspace Administration of China effectively ended online anonymity here by making Internet companies responsible for ensuring that anyone who posts anything is registered with their real name.
It has cracked down on the VPN (virtual private network) systems that netizens have used to jump the firewall and evade censorship, with Apple agreeing to remove VPN providers from its Chinese App Store in July and authorities detaining a local software developer for three days last month for selling similar services.
This month, authorities dramatically expanded their controls over what people say in private online chat groups, making anyone who sets up a chat group legally responsible for its content and requiring Internet companies to establish systems to rate and score the online conduct of users — to ensure they follow the Communist Party line and promote "socialist core values."
Those scores would ultimately be integrated into a still-developing system of "social credit" — a sort of credit rating for individuals that could determine access to anything from financial services to transport and foreign travel.
The latest chat rules deal another major blow to citizens' already diminished rights to express opinions online, said David Bandurski, co-director of the China Media Project and a fellow of the Robert Bosch Academy in Berlin. He called it one of the strongest indications yet of the party's "atomization and personalization of censorship."
More than half of China's population is now online, more than 730 million Internet users spending much of their personal and commercial life in cyberspace and fueling the largest e-commerce market in the world.
But as China moves to becoming a fully digital society, where cyberspace is the "land, sea and sky" of citizens' lives, the party is claiming and consolidating its power over this domain, Bandurski said.
"Each of the regulations we see coming out in recent months, in the wake of the overarching Cybersecurity Law, is about extending political and administrative authority to every aspect of cyberspace," he said.
The latest crackdown is a reflection of the importance that chat groups have in shaping public opinion, said Bill Bishop, publisher of the Sinocism newsletter.
It may also have been stepped up ahead of another key summit next month, when Xi Jinping is due to be formally granted another five years in power as Communist Party general secretary.
Accusations of high-level corruption leveled by exiled billionaire Guo Wengui, often disseminated over Twitter and YouTube, also have "touched a nerve," said Xiao Qiang, an adjunct professor at the University of California at Berkeley and founder of the China Digital Times website.
Those short-term factors may have encouraged some of the latest moves to expand controls. "But overall, they are part of a larger government plan," he said.
The Great Firewall works to exclude news and information that might threaten the Communist Party's hold on power, as well as foreign social media networks such as Facebook and Twitter that might allow private citizens to join forces.
The government, however, long knew and accepted that a small percentage of its population circumvented the firewall using VPNs, deeming it important not to alienate domestic and foreign businesses, academics and the English-speaking elite.
Yet as VPN use expanded to an ever greater share of the population and also became increasingly employed even by party officials, the authorities apparently decided they had to draw the line, experts said.
Apple said its cooperation in that effort was compelled by the need to observe Chinese laws, but it was condemned by activists and companies working to circumvent censorship.
"Apple removing VPN apps from the App Store effectively removed access to the Internet for billions of people," said Sunday Yokubaitis, president of Golden Frog, which oversees VyprVPN. "The Internet is information, and any disruption of Internet access is censorship."
Yokubaitis said he was also concerned that Apple had set a dangerous precedent for other countries with restrictive regimes, such as Russia or Iran.
The Communist Party has long tolerated a certain amount of public criticism online, as long as citizens did not try to group together. But even that safety valve is gradually being throttled, experts say.
Critics have called the system of social credit an unholy alliance between big data and Big Brother. Yet in a sense, it is a return to some of the Communist Party's practices under Mao Zedong, updated for the digital age, experts say.
"It is menacing, although in some ways merely a return to the situation in the 1960s and '70s, when you had to fear that your neighbor would rat you out because you listened to a shortwave broadcast from the BBC or said something negative about Chairman Mao," said Jeremy Goldkorn, an expert on China's Internet and editor of the SupChina newsletter. "But the food is much better now."
Bandurski says it is time to update the idea of a Great Firewall — meant to insulate China from external contagion — to think instead of a "Great Hive" of propaganda and firewalls around the individual, a nest of connections the party can sever and control at will.
"All may share in the collective illusion that they are part of a thriving humming space, but all are joined in the party's re-engineered project of guidance and managed cohesion — and all are buzzing at more or less the same frequency," he wrote in a China Media Project piece.
Lester Ross, partner-in-charge of the Beijing office of the WilmerHale law firm, said the rising Internet controls are "inconsistent with China's stated effort to attract more international talent and will reduce China's ability to compete in the creative industries."
The latest controls did provoke some criticism online, but experts doubt they will generate a major backlash just yet.
"As long as the economy does not collapse, I think most Chinese, like Americans, will put up with extensive digital surveillance and the possibility of trouble from online speech — in exchange for on-demand delivery of chocolate moon cakes and selfie apps that beautify your face in photos," Goldkorn said.
Amber Ziye Wang contributed to this report.