WASHINGTON—The Cuban government has finally blocked access to a Web log written by Yoani Sanchez, a young woman who has caused a sensation on the communist-ruled island with her daily postings about life in Havana. But she says she has found a way to outsmart her censors. In the spirit of Soviet-era samizdats and Czechoslovakia’s Charter 77, her blog, www.desdecuba.com/generaciony, lives on.

Sanchez is a linguistics graduate in her early 30s, with a husband more than two decades her senior and a 12-year old son. Her parents sent her to a revolutionary school in rural Cuba, where she became a young communist “pioneer.” But once she graduated from college, she was unable to pursue an academic career because her thesis on dictatorships in Latin American literature sounded, to the authorities, like a chronicle of life at home. She and her husband eke out a living by providing services to tourists.

In order to blog, Sanchez has been sneaking into Internet cafes in hotels reserved for foreigners. A typical visit involves quickly uploading her blog entries from a flash memory card to her Web site, which is linked to a server in Germany.

Since only 200,000 Cubans—out of a total of 11 million—have access to the Internet, it is unclear how many of her compatriots read her postings. But apparently many do. Apart from legal users, mostly government employees and researchers, there are countless clandestine Internet links in homes around the country. The blog has become so popular inside and outside Cuba that it received 1.2 million visits in February alone.

A measure of her popularity is how quickly the word spread that the government had blocked access to the blog last week. “It will seem amazing that with such a limited access to the Internet, Cubans have noticed the censoring of these Web pages so quickly, but it was so,” she wrote. “After being warned by many nervous readers, I went to a cybercafe and confirmed the censorship.”

It is ironic that the clampdown should have taken place precisely when Raul Castro is lifting restrictions on the sale of computers, DVD players and cell phones. After all, the brother of Fidel Castro has been encouraging Cubans to debate problems openly—the reason why, in a famous incident depicted on YouTube and other sites, Eliecer Avila, a student from Havana’s University of Computer Science, confronted Ricardo Alarcon, the head of the National Assembly, over restrictions on travel abroad. With a straight face, Alarcon explained that there are 6 billion people in the world and that it would be impossible for all of them to fly at the same time.

Sanchez’s blog has responded to the challenge in characteristic style: “The anonymous censors of our famished blog have tried to lock me up in the room, turn my lights off and prevent my friends from coming in.... However, the punishment is so useless that it invites pity and so easy to elude that it becomes an incentive.”

What has probably unnerved the regime is not so much her attacks on the Castro brothers as her vivid description of daily life—how Cubans register their cows as oxen to avoid having to sell the milk to the government, how people get paid in worthless Cuban pesos but have to obtain “convertible pesos” on the black market in order to buy soap, and how the timid reforms put in practice by Raul Castro so far amount to the legalization of global technology that is beyond his control. Still, she despairs the pace of reform. In one entry, she says that the toaster will come “in two years’ time ... satellite dishes will arrive in the middle of the century and my grandchildren will get to know GPS in their teen years.”

Where does this woman get her courage? A little anecdote from a recent entry in her blog perhaps contains a clue. Referring to her family’s Easter celebration, she regretted that there would be an empty chair because of a missing relative—Adolfo Fernandez Sainz, one of the 75 independent journalists jailed by the Castro regime five years ago. And she expressed the hope that no one would deserve the phrase hurled at her by her young son when he learned of those detentions: “So, you are still free because you are a bit cowardly.”