WikiLeaks has announced on Monday the publication of millions of email exchanges obtained from controversial international security expert Strategic Forecasting Inc (Stratfor), which WikiLeaks founder Julian Assange has accused of targeting activist groups.

WikiLeaks, according to Reuters, provided no details on how it obtained the documents that it plans to leak starting this week though Stratfor has earlier reported a breach on its computer system in December 2011.

Media reports attributed the hacking incident to a mysterious alliance of global hackers known as Anonymous, whose exploits last year include the high-profile incursions on computer systems of top global firms and selected governments.

Stratfor chief executive George Friedman admitted in January that company emails were indeed accessed by hackers but assured too that no important information were lost during the reported hack attack.

"As they (hackers) search our emails for signs of a vast conspiracy, they will be disappointed," Friedman was reported by Reuters as saying in a statement he issued last month.

At most, the Stratfor chief allowed that the email correspondences, which he said were mostly exchanges sent and received by company employees, would reveal the security firm's dealings with governments and corporations across the globe.

"We have relationships with people in the U.S. and other governments and obviously we know people in corporations, and that will be discovered in the emails," Friedman said.

"We are what we said we were: an organization that generates its revenues through geopolitical analysis. At the core of our business, we objectively acquire, organize, analyze and distribute information," the company chief added.

But processing information and security consultancy are but the top layer of Stratfor's foremost functions, according to Assange.

The company even admitted that it employs intelligence tactics in performing its core business and its base customers were mostly composed of high-profiles personalities and entities, chief among them is the U.S. government and U.S. government officials, both active and retired.

"Here we have a private intelligence firm, relying on informants from the US government, foreign intelligence agencies with questionable reputations, and journalists," Assange told Reuters.

He added that information gathered by Stratfor were not always utilised to monitor activities of groups deemed as risks to global security.

"The targets of this scrutiny are, among others, activist organizations fighting for a just cause," Assange stressed.

The Australian-born Assange ran afoul with the U.S. and other major governments when WikiLeaks started publishing last year leaked documents that detailed the diplomatic operations of these nations.

The accounts carried by the leaked cables were mostly ignored but not denied by the concerned governments, giving Assange some semblance of credibility and further boosting his popularity.

He now faces allegations of sexual assaults in Europe, which he claimed were concocted by those wanting to silence his anti-secrecy website.