China typically blocks access to the World Wide Web around important national holidays, such the 60th anniversary of the founding the People’s Republic of China next Thursday. With so many sites blocked already (YouTube, Facebook, Blogspot, to name but a few), I guess the censors decided the surest way to cut off potentially inflammatory websites was to choke the Tor network off.

Of course, there are ways around the newest layer of bricks in the Great Firewall of China.

I noticed something was fishy when I tried to connect to Facebook using Tor. My Tor client couldn’t complete the connection to the network. My little onion stayed yellow, and never went to green.

Tor uses a decentralized network of proxies scattered around the world. The Tor client checks a list of active proxies (computers acting as go-betweens), then logs into the network using one or more of the proxies. An add-on to Firefox then switches Firefox over to use the proxy to access the WWW.

An active Tor connection displays a green onion icon in the Windows taskbar. A pending one shows a yellow onion. The icon refers to Tor’s “onion routing” of connections to make tracing difficult.

Checking the Tor client’s message log, I discovered the client was only finding a few of the thousands of proxies on the network, and stalling in its search for more. A quick survey on Google confirmed my suspicions; China was blocking the Tor proxy network by choking off access to the public Tor proxy directory, for the first time since I’ve been here.

But, Tor designers prepared for such an eventuality. You can add “bridges” — unpublished proxies — manually to the Tor client’s network configuration. Once I discovered how to get the bridges, I was back in business checking out Facebook. (YouTube still remains off limits, because the Firefox add-on’s treatment of Flash. I can get to YouTube, but I can’t view the vids. I’ve been too lazy to try to fix it.)

To get three unpublished bridges, you have to send an email to “bridges [AT] torproject [DOT] org” using a Gmail account. Only Gmail messages are accepted, for security reasons. The subject line should be blank, and the message body should just say, “get bridges” (without the quotes). In less than a minute, the reply gives you three bridge IPs and brief instructions on what to do with them.

There is another Firewall hopper called “Freegate,” which I have not tried yet. Predictably, it is nearly impossible to download from within China right now, even by going to the CNET download site. Another web-based proxy, sneakme.net is likewise being blocked. It was accessible only a couple of weeks ago.

So far, Google, Wikipedia, and all Western news sites are still open without resorting to sneaky IP legerdemain. I am hoping the net nannies don’t get that paranoid.

JISHOU, HUNAN — Sometime this evening, the Chinese net nannies blocked access to Google.com, part of the government’s ever continuing struggle to combat (officially) pornography and (unofficially) access to sites critical of the government.

True to form, the state’s censors are using Google as a poster child to warn those who might want to buck the censors.

CCTV, the state-run television, had a report earlier this week blaming Google for “providing ‘vulgar and unhealthy’ content.” The report featured an interview with a young man – later discovered to be a CCTV intern — who said his roommate had become addicted to porn thanks to Google’s help.

State censors then blocked the intern’s name (Gao Ye 高也) from permissible searches at Google China, the Chinese (net nannied) version of Google.com. Google.cn apparently agreed last week to restrict access to porn, so we can still use it. But, the Great Firewall of China is now blocking the international site,Google.com, which joins youtube.com, blogger.com and blogspot.com on the no-no list.

Experts suggest that the government’s anti-porn crusade is a smokescreen to block access to politically sensitive websites. We lost access to Youtube, for example, after videos of Chinese soldiers beating Tibetan monks showed up there, and blogger and blogspot went dark around the time of the 20th anniversary of the Tian’anmen Square Massacre earlier this month.

Blocking Google.com might serve the same function, or as the articles at Danwei.org suggest, the sudden crackdown may be retaliation for national and international protests about new forms of government censorship.

A few weeks ago, China announced that by July 1 all computers sold in China must have a web-filtering program installed called Green Dam Youth Escort, supposedly to prevent children accessing porn and violent material. Chinese netizens instantly cried foul, and most have mocked the program as a thinly veiled attempt to censor the Internet. (One example of mockery is shown here: Green Dam Girl (绿坝娘) is pulling down Windows XP Girl’s knickers.)

Another group of Chinese netizens proposed a national boycott of using the Internet on July 1, the deadline by which manufacturers must provide Green Dam on new computers.

Computer experts at the University of Michigan then alleged Green Dam was a security risk, allowing external computers access to a user’s files and Internet browsing history. The UMich analysts recommended users uninstall Green Dam ASAP.

Representatives of a US software firm, Solid Oak, accused Green Dam’s developers of stealing code from Solid Oak’s own Cyber Sitter web-filtering application.

Finally, the US government weighed in on Monday, saying it had grave concerns on how Chinese Internet censorship would affect trade and access to information.

China, however, remained resolute yesterday in requiring Green Dam on new computers.

Blocking Google.com, then, may be a way for the Chinese censors to show us all who’s boss, in a virtual pissing contest. (Though, as I have reported earlier, there are ways to circumvent the Great Firewall of China. It’s cumbersome, but it works.)

On a more personal level, losing access to Youtube and Blogger/Blogspot was a nuisance, but a minor one. Losing Google.com, however, means I cannot easily access my photos at Picasaweb or use www.gmail.com to read my email and access my contacts files. [I can still check my gmail using Thunderbird and Yahoo! Mail, though. Only Web traffic is being restricted so far, not POP/IMAP/SMTP traffic.]

It’s impossible to say how long Google.com will be blocked. When I arrived last August, I found that Livejournal.com was blocked, then sometime this spring the ban was lifted. In true authoritarian form, Chinese censors giveth, and they taketh away.