Quotes of the Day

The e-mail appeared to come from me. It began with something I'd previously written. Then the font changed and the English degenerated. "Attched [sic] is I want to know and discuss the issues," said the note to the new leader of the Tibetan government-in-exile in Dharamsala, India. Lobsang Sangay was savvy enough to figure out that neither the message nor an attachment in Chinese were really from me. The Tibetan PM wanted to let me know that someone had hacked my work e-mail account and pressed "reply." But before he began composing a warning, he saw that the reply was not being automatically routed to me. Instead, the "to" field bore the e-mail address of the private secretary of Tibet's exiled spiritual leader, the Dalai Lama. It looked as though my e-mail was designed to spread virally to other users and cause maximum confusion.

We are all alert to the perils of online communication, of suspicious financial requests from supposed Nigerian bankers or friends who have apparently lost their wallets in remote capitals. But people in China have an especially fraught relationship with the Internet. It's not just that the Great Firewall of China limits access to sites like Facebook, Twitter, YouTube or Blogspot. More disquieting is the realization that every word typed may be under surveillance and every e-mail or post prone to infiltration. Yes, snooping happens in Western countries too. But China has tens of thousands of trained monitors. The nation's tech companies employ huge teams to comb their servers and delete any material the government deems unfit for public eyes.

Then there's the overt meddling. I'm one of many foreign journalists in China who have had their e-mail accounts hacked. Some have found that all their messages were being auto-forwarded to mysterious e-mail addresses. Who is doing this? I can't say for sure. But Google has accused hackers in China of breaking into Gmail. In August, the world's biggest security-technology company, McAfee, released details of Operation Shady RAT, a five-year infiltration of around 70 large computer networks, including those belonging to the U.S. and Taiwan governments, the International Olympic Committee and the Associated Press. Cybersecurity experts speculated that no power but China would be interested in those targets. Beijing dismissed the allegation.

Perhaps the worst part of going online in China is the uncertainty. One day, jasmine is a flower. The next day it's a revolution, and a banned search word. Even with a laptop that connects to a VPN — a virtual private network, which for a fee is supposed to enable users to circumvent the Great Firewall — I can't access Facebook or other banned sites in my Beijing apartment. (The laptop works O.K. in the office, unless it's the anniversary of the Tiananmen massacre or another sensitive date, in which case certain sites are still blocked.) The net effect of this interference is a blunting of curiosity. I really don't need to Google that term, right? A dangerous lassitude takes over.

Visiting foreign businessmen are often shocked when they experience virtual China firsthand: something as simple as updating a Facebook status — "Just arrived in Shanghai!" — is forbidden. China is the world's second largest economy. Can it really get away with online restrictions more suited to Cuba or North Korea? It seems so. This summer, Beijing began requiring public wi-fi in coffee shops and other locations to be routed through monitoring software that public-security officials can access. The world shrugged.

Most of the 500 million Chinese online aren't using the Internet to foment political upheaval. They do what many people anywhere else in the world do: access dating sites, play games, look at porn. Nevertheless, in a society where traditional media is restricted by even more onerous directives, the Internet is the freest space. Twitter may be blocked, but domestic look-alike Sina Weibo hosts some 200 million microbloggers. In the hours (or seconds) before the censors kick in, microblogs serve as crucial clearinghouses of free information, like in July when a high-speed train crashed and an official cover-up ensued.

But now Sina Weibo and Chinese social-media sites are the target of a new government crackdown. In recent weeks, officials have dropped by Sina Weibo's offices to remind employees of their patriotic duties. The State Internet Information Office, a body set up this year, warned citizens last month not to spread "malignant tumors" online. The Politburo is also mulling over "cultural reforms" that would restrict the Internet further — and presumably lead to a growth in the number of online snoops. Just be careful if you get an e-mail from me.

This article originally appeared in the Oct. 24, 2011 issue of TIME Asia.

• Hannah Beech
• But amid Beijing's online meddling, you might never know who sent it