Activists and a group of former spies have launched a huge campaign to defend WikiLeaks and target corporations seeking to suppress the whistleblowers' site.
'Hacktivists' yesterday organised major online 'denial of service' assaults on MasterCard, Visa and Paypal, freezing their websites in Europe and the USA and delaying or blocking payments.
They are furious that the companies have been refusing to process donations to WikiLeaks, which has offended the American and other governments through its publication of secret US cables and documents.
The companies have claimed that they have not been seriously affected, but the BBC was contacted by a payment firm linked to Mastercard that said its customers had "a complete loss of service".
An authentication service for online payments known as Mastercard's SecureCode has been disrupted. Visa has had similar problems.
The campaign is called 'Operation Payback', and its 'Avenge [Julian] Assange' activities are also targeting US politicians Joseph Lieberman and Sarah Palin, PostFinance in Switzerland, Borgstrom and Bostrom, and the Swedish Prosecuting Authority.
Meanwhile, WikiLeaks is continuing to release documents, with assistance from mirror sites, campaigners and individuals across the world - who have ensured that the site remains functional, despite cyber-attacks from the US government, China and others.
Material relating to the Vatican and Israel is described as "in the pipeline", and could be released within the next few days.
The political storm around WikiLeaks has now turned into a fully fledged cyber battle, with grassroots groups on one side and large corporations and governments on the other.
Facebook is now under fire for closing down the Operation Payback page yesterday.
Mark Stephens, the lawyer of WikiLeaks editor-in-chief Julian Assange, who was on 7 December denied bail in a UK court on sexual assault charges levelled against him in Sweden (which he strenuously denies), had said on 8 December that he thought the campaign to defend the group and its website would "go viral".
A group of ex-intelligence officers from the CIA, FBI and the British secreat services has also written an open letter of support for Mr Assange and WikiLeaks.
Led by Daniel Ellsberg (the former US military analyst who leaked the Pentagon Papers in 1971, exposing information about the Vietnam War) the statement declares: "WikiLeaks has teased the genie of transparency out of a very opaque bottle, and powerful forces in America, who thrive on secrecy, are trying desperately to stuff the genie back in."
Mr Ellsberg says that labelling the Pentagon Papers leak as 'good' whilst the Cablegate leaks are 'bad' makes no sense. "That's just a cover for people who don't want to admit that they oppose any and all exposure of even the most misguided, secretive foreign policy. The truth is that every attack now made on WikiLeaks and Julian Assange was made against me and the release of the Pentagon Papers at the time."
WikiLeaks (http://220.127.116.11/) describes itself as "a non-profit media organisation dedicated to bringing important news and information to the public. We provide an innovative, secure and anonymous way for independent sources around the world to leak information to our journalists. We publish material of ethical, political and historical significance while keeping the identity of our sources anonymous, thus providing a universal way for the revealing of suppressed and censored injustices."
A variety of ways of supporting WikiLeaks financially are still available, and detailed here: http://18.104.22.168/support.html