To understand what the web has done for free speech, it’s necessary to think about how Natalya Gorbanevskaya and her fellow dissidents produced 65 issues of the samizdat publication Chronicle Of Current Events in the Soviet Union between 1968 and 1983.

Censoring the web poses a significant challenge to authoritarian rulers everywhere, and often involves fine-grained judgment calls.The Soviet state controlled access to printing presses and photocopiers. So when it was time to publish, Gorbanebskaya would tap out six identical copies of Chronicle on a contraband typewriter. Next, she distributed these editions to six friends, who would, in turn, type out further copies before distributing them to additional readers.

Distribution was slow and extremely risky. Like dozens of others involved in the production of Chronicle, Gorbanevskaya was arrested by the 9th Division of the Fifth Chief Directorate of the KGB, which was specifically charged with rooting out samizdat. In 1969, she was diagnosed as a schizophrenic and confined to a mental hospital for three years.

Today, there are only two countries in the world where censorship-induced paralysis exists on anything like a comparable scale: Burma and North Korea. Everywhere else, the terms of trade between free speech and censorship have improved since the Cold War.

Technology has been responsible for most, perhaps all, of this improvement. Behaving like water, information on the web always seeks the largest possible audience. In doing so, it continues to exert pressure on the adamantine surface of oppression.

The experience of Iran suggests that the results can be significant. The Berkmann Center for Internet and Society at Harvard University suggests that 35,000 regularly-updated blogs are written in Arabic worldwide. Yet a separate Berkmann study suggests that as many as 70,000 active blogs are written in Farsi.

According to Technorati, the lingua franca of the Islamic Republic of Iran – spoken by an estimated 75 million people worldwide – ranks among the web’s top 10 most popular blogging languages.

“If you look around the Arab world,” one member of Dubai’s digerati told me during a visit to the emirate last week, “you’ll see that blogging and social media is taking off fastest where repression is most severe.”

You won’t hear such criticism of Dubai’s ruling class on the airwaves or in print. Yet technology enables their expression around the fringes of public life.It’s also true that censoring the web poses a significant challenge to authoritarian rulers everywhere. Unlike the Soviet drive to wipe out samizdat publishers, it often involves fine-grained judgment calls.

The Chinese government, for example, recognizes that the web can keep its citizens entertained (and therefore quiescent). It also recognizes that web access – and the accompanying access to ideas and inspiration – is an indispensable driver of economic growth. Under these circumstances, deciding what to censor can become difficult and expensive.

In many cases, the playing field is more level than it was for Natalya Gorbanevskaya. Measures call forth counter-measures. In Beijing, on 15 June, for example, 2.3m soldiers in the People’s Liberation Army were banned from blogging. Yet in Paris, ten days later, the advocacy group Reporters Without Borders set up a virtual private network designed for journalists, bloggers and dissidents who wish to evade eavesdropping.

In addition, it’s nice to imagine – as Clay Shirky did last week at the Guardian’s Activate conference – that dissidents hold a trump card: the absence of hubris. Power tends to make rulers “certain of what will happen next”, said Shirky. As a result, rulers “try fewer things” than dissidents, who excel in terms of creativity. Meanwhile, as Shirky argues, “the wiring of the population” is “complete to the first degree”. Even North Korea has a mobile phone network.

But what happens when information, like water, does its work? What happens when barriers to free expression come crashing down?

Westerners typically envisage free expression being accompanied by profound political consequences. From the English Civil War to the French Revolution, the model for this kind of transition feels deeply familiar.

But is this model applicable everywhere? What, for example, will happen when the voices on the other side of content-filtering walls become too loud in a place like Dubai?

A US-friendly emirate in a strategic location, Dubai’s social and cultural norms are rooted in the past. Everything else about the city, including its rampant consumerism, is predicated upon fast-forwarding to the century’s end.

Like governments everywhere, Dubai’s government operates in the present tense. Not surprisingly, perhaps, it’s described by the OpenNet Initiative as an “extensive” censor of the web. The authorities block any web site deemed to be “inconsistent” with the government’s “religious, cultural, political and moral values”.

In practice, this means difficulties for sites that specialize in nudity, sex, dating, gambling, religion, alcohol, drugs, anonymizer tools and VoIP applications. For its part, traditional media censors itself, wary of selective enforcement of draconian laws.

The society on which bloggers and journalists pass comment rests on a series of significant fault lines. In a city of 1.7 million , for example, four out of five inhabitants are migrant workers, many of whom live in conditions described by Human Rights Watch as “less than human”.

At street-level, Dubai is a city of Pakistanis, Indians, Chinese and Iranians. Only in comfortable air-conditioned offices and hotels does the emirate suddenly become Arabic. When wealthy local women go shopping, indentured servants trail behind them, carrying their bags. The glittering shopping malls they patronize are studded with prayer rooms for spiritual contemplation.

To western eyes, the contradictory feudalism of Dubai is disorienting. Last week, a taxi driver from Peshawar who drove me around the city hinted at the tensions that exist beneath the surface. “The locals are good for only three things,” he told me dismissively. “They eat, they sleep and have sex.”

You won’t hear such criticism of Dubai’s ruling class on the airwaves or in print. Yet technology enables their expression around the fringes of public life. James Piecowye, an expat Canadian who hosts a radio talk show in Dubai, tells a story that captures the fragility of censorship in a society that isn’t accustomed to speaking its mind.

Recently, Piecowye was talking live, on air, about “something that couldn't be said” because of the emirate’s media laws. At this point, he received a text message from a listener that read as follows: “We know what you're trying to say, so why don't you just SAY it!!”

Dubai isn’t a failed state, or a famine-wracked totalitarian basket case. Among those born in the emirate, life expectancy is 78 years. Slightly less than 90 percent of the local population can read and write. Yet the natives of Dubai live their long and literate lives in a society where public debate is frequently non-existent.

In places like this, much the web’s leveling work remains to be done, with consequences that remain unpredictable.