Update, Wednesday: In a video, Anonymous has said the idea that they would take down U.S. power grids is “ludicrous.” Watch the full video.

A number of Wall Street Journal Facebook pages were the subject of a comment flashmob Tuesday, claimed by Anonymous, just hours after the Journal published a report that warned the hacker group was getting more powerful.

Protesters wearing Anonymous Guy Fawkes mask demonstrate in Budapest in February against a law protecting online copyright. (ATTILA KISBENEDEK/AFP/GETTY IMAGES)

The Anonymous Kollektiv, believed to based in Germany, told participants to copy the following message on Journal sites:

“Dear editors of the German Wall Street Journal, You equated Anonymous with al-Qaeda in your February 2012 article and the related coverage. With this type of coverage you may be able to stir up fear in the United States, but not in the land of poets and thinkers! With this comment, we would like to oppose the deliberate dissemination of false information and express our displeasure with your lobby journalism. We are Anonymous. We are millions. We do not forgive. We do not forget. Expect us!”

The Wall Street Journal report, which cited a number of security officials, warned that the hacker group could take down the U.S. power grid within a couple of years. One official quoted also said that the U.S. should be wary of a foreign government or al-Qaeda trying to hire the hackers to mount a cyber attack.

Until now, Anonymous has focused on attacking the Web sites of government agencies, financial companies and security firms. The Web sites go down, but then they come back up. Anonymous has also leaked sensitive phone calls and personal information, but the consequences have been limited.

The hacktivist group has also so far made no indication that suggests it would attack the power grid. But one message posted to pastebin suggests the group could be planning to “take down the Internet” on March 31. And some officials told the Journal the group is gaining the numbers and capability to pull off a large-scale attack.

“A near-peer competitor [country] could give cyber malware capability to some fringe group,” Gen. Martin Dempsey, chairman of the Joint Chiefs of Staff said at a hearing last week, the Journal reported. “Some hacker, next thing you know, could be into our electrical grid. We have to get after this.”

Related links:

Innovations: Have we lost control of the Internet?

Innovations: Meet the new political elite

Vivek Wadhwa: America, your dissidents are your power

The academics of Anonymous

View Photo Gallery: It used to be that being a big donor, a pundit, an elected official or elder statesman was the way into the political elite. Today, it’s through HTML, javascript and ruby — in other words, computer programming.