WikiLeaks, the whistleblowing website, has started publishing more than 5m emails it claims to have obtained from a US political risk consultancy that has been described as the "shadow CIA." The emails could expose sources and intelligence gathered by Texas-based Stratfor, whose clients include a number of large corporations including BT, BAE Systems, Apple, Microsoft, Coca-Cola and Google. The attack exposed credit card numbers and personal data. Members of Anonymous also claimed they had emails from about 100 employees, which they would publish. Stratfor confirmed that a number of emails had been stolen in the December attack and described the action as "a deplorable, unfortunate - and illegal - breach of privacy." Having had our property stolen, we will not be victimised twice by submitting to questioning about them," said the company. This is another attempt to silence and intimidate the company, and one we reject. The first 200 emails, released on Monday, appeared to shed light on the internal workings of Stratfor, including a complex network of informants and covert payments. Stratfor's biggest customers were oil companies and government agencies, according to documents published by WikiLeaks. The emails also showed that Stratfor, which describes itself as a company providing geopolitical analysis, had been hired to provide information on activists and campaigners. The company appeared to have been hired by Dow Chemical to provide information on campaigners related to the Bhopal accident and by Coca-Cola to get details of PETA activists around the time of the Vancouver Olympics. WikiLeaks said it also had found more than 4,000 emails mentioning Julian Assange, the WikiLeaks founder. "The material contains privileged information about the US government's attacks against Julian Assange and WikiLeaks and Stratfor's own attempts to subvert WikiLeaks," wrote the WikiLeaks website. The Financial Times has not been able to independently verify the authenticity of the emails. Australian-born Mr Assange is under house arrest in the UK as he appeals against an extradition order to Sweden, where he is accused of sexual crimes. Since the release of 251,000 US diplomatic cables in late 2010, WikiLeaks has been embroiled in clashes with financial services firms and politicians. Payment firms including MasterCard, Visa and PayPal in December stopped processing donations to WikiLeaks, which has become a problem for the site's financing. WikiLeaks said it was working with two dozen media organisations worldwide, including L'Espresso and La Repubblica newspapers in Italy, Rolling Stone and Russia Reporter, to analyse and publish the new emails.