The ex-CIA employee and whistleblower Edward Snowden posted hundreds of messages on a public internet forum railing against citizen surveillance and corporate greed, it was revealed today.
Mr Snowden, who leaked details of US internet surveillance to a British newspaper, posted the messages under a pseudonym during the eight years that he worked for the CIA and the NSA.
Details of the postings were revealed by Reuters and came as the UK government warned airlines worldwide not to fly Mr Snowdon to Britain as "the individual is highly likely to be refused entry to the UK".
"I can't hope to change the way things are going by overtly complaining, writing letters, or blowing things up," Snowden wrote in 2003 in response to a discussion about corporate greed on the Ars Technica online forum.
"That's not the way a good person does things. I will, however, do what I can with the tools that are available to me."
Snowden was also a prolific commentator on the technology forum Ars Technica, posting approximately 750 messages using the screen name "The True HOOHA" from late 2001 to 2012.
According to Reuter's sources Snowden was employed by an unidentified classified agency in Washington from 2005 to mid-2006, by the CIA from 2006 to 2009, when he primarily worked overseas, and by Dell Inc from 2009 to 2013, when he worked in the United States and Japan as an NSA contractor.
The revelations came as intelligence officials were grilled by US lawmakers about how the 29-year-old high school dropout managed to gain access to such top secrets as the NSA's electronic surveillance programs.
Most of the postings were not political in nature: he dispensed advice about government careers, polygraphs and the 2008 stock market crash. He claimed to own the same gun as James Bond and posted glamour photos of himself. He jokingly compared the video console Xbox Live to NSA surveillance.
One of his postings, however, dealt with the now familiar issue of corporate compliance with government eavesdropping programs. On February 4, 2010, while working for Dell, Snowden commented on a discussion about a major technology company that allegedly was giving the U.S. government access to its computer servers.
"It really concerns me how little this sort of corporate behavior bothers those outside of technology circles," Snowden wrote. "Society really seems to have developed an unquestioning obedience towards spooky types."
It is not clear if his former employers knew about his online persona. The CIA, NSA, Dell and Booz Allen Hamilton - which most recently employed Snowden - declined to comment.
Additional reporting by Reuters