AS CHINA’S prime minister over the past decade, Wen Jiabao was often described as a populist and reformer, sometimes nicknamed “Grandpa Wen” because of his folksy willingness to meet ordinary people. One of Mr. Wen’s refrains was that Chinese officials at all levels should declare their personal assets, and those of family members, in an effort to fight corruption. Mr. Wen suggested that the information should be published for all to see.

On Friday, the New York Times took Mr. Wen at his word and published an eye-opening exposé that revealed that members of his family control assets of some $2.7 billion, including interests in banks, jewelers, tourist resorts, telecommunications companies and infrastructure projects, some of it held in offshore entities. The article marks yet another startling glimpse into how China’s leading families, many of them descended from Mao’s generation, have used their power to become fabulously wealthy. The ouster of Bo Xilai as boss of Chongqing and the subsequent prosecutions in an alleged graft and murder scandal provided another showcase example this year.

As soon as the Times article was published, China’s Internet censors forgot about Mr. Wen’s desire for more openness. China blocked both the English and Mandarin Web sites of the Times so that hundreds of millions of its citizens could not read the account online. China also rushed to block mention of the story on popular Twitter-like microblogs known as weibo, where users often are quick to call attention to official malfeasance. A similar Web blackout was imposed this summer after Bloomberg News described the accumulation of assets by relatives of Xi Jinping, who is expected to become China’s next Communist Party leader and president.

The sudden blackout belies the supposed confidence of China’s ruling elite for having built an economic superpower and shows them to be utterly at odds with the global digital revolution. Their attempt to block it underscores how deeply China’s rulers fear that the truth, if fully known, would undermine their legitimacy.

Beyond Mr. Wen’s personal discomfit, the Chinese leaders are sitting on a powder keg. Public anger is growing at the gap between rich and poor and at an epidemic of official corruption. A survey of Chinese citizens published this month by the Pew Global Attitudes Project showed that 81 percent of those questioned agree with the statement that the “rich just get richer while the poor get poorer.” Half of the respondents said corrupt officials are a “very big problem,” up 11 percentage points in four years. Recently, a local official in Shaanxi was ousted after microblogs distributed photos of him wearing expensive luxury watches.

Rather than unplug the Internet, Mr. Wen would show more wisdom by reaffirming his earlier desire for more transparency and disclosure. In the long run, it is the only way to build trust with China’s people and the only route to becoming a real superpower in today’s world.