Multi-national companies are under sustained attack from a worldwide alliance of hackers.
As the 39-year-old Australian editor-in-chief of WikiLeaks languished in Wandsworth Prison accused of sex offences, the financial and technological giants that withdrew support from the website in the face of pressure from the US government were hit by online hacking attacks, paralysing their net operations. MasterCard's website was downed.
Another of the companies, PayPal, confirmed that it had only stopped collecting donations for WikiLeaks after intervention from the US State Department – fuelling suspicions that the US is leaning on businesses to strangle support for the website, which is involved in the embarrassing leak of 250,000 American diplomatic cables.
The plot thickened when WikiLeaks revealed that diplomats from the US had intervened to try to amend a draft law going through Russia's Duma which would have hit Visa and MasterCard. Hours before, the two companies had announced they were cutting their ties to WikiLeaks.
The cable, dated 1 February 2010, disclosed that the Obama administration lobbied senior Russian government officials on behalf of the firms against a plan by a consortium of state-owned banks to collect processing fees "estimated at $4bn [£2.5bn] a year".
Meanwhile WikiLeaks, itself destabilised by cyber attacks, emerged phoenix-like as hundreds of "mirror websites" sprang across the web, enabling computer users to view its latest disclosures.
Acting as Mr Assange's avengers, a global group of hackers calling themselves "Anonymous" paralysed the MasterCard website by overwhelming it with requests for information. In a message on an internet bulletin board, they threatened to target the social-networking site Twitter in protest at the "censoring" of the group's discussion boards – which the US firm denied.
One anonymous "hactivist" wrote on the forum 4chan: "The longer we fire MasterCard, the better." Another urged: "Keep attacking, let's make it a war, not a battle like what usually happens."
Hackers also struck against the website of the Swedish lawyer who represents the two female Swedish WikiLeaks volunteers at the centre of the Assange sex-crimes case. The lawyer, Claes Borgstrom, who reported the hacking to police, said their claims were not a politically motivated plot against Mr Assange. He said: "It has nothing to do with WikiLeaks or the CIA."
Cyber attacks were also launched against the Swiss postal system's financial arm, PostFinance, which this week shut Mr Assange's new bank account containing a defence fund of £26,000.
The corporate hacking, codenamed Operation Payback, is a response to a week-long series of business retreats from WikiLeaks, which began when Amazon removed the site from its servers. Amazon denied US pressure had prompted it to remove the data.
The American data firm EveryDNS also dropped WikiLeaks from its entries last Thursday, saying that hacking attacks against WikiLeaks were threatening its ability to host thousands of other sites. At the weekend, PayPal announced it was halting its collection of donations, later revealing that it had been "advised" by the US State Department that WikiLeaks' activities were illegal.
Speaking before he was remanded in custody, Mr Assange said the corporate action against him amounted to the "privatisation of state censorship" in the US. "These attacks will not stop our mission, but should be setting off alarm bells about the rule of law in the US," he said.
So far this year, the not-for-profit organisation has leaked 400,000 classified US war files from Iraq, 76,000 from Afghanistan and is working through the 250,000 US diplomatic cables.
The US Secretary of State Hillary Clinton has said the leaks are an illegal attack on the US and the international community. But yesterday, one of America's allies chose to blame the US rather than WikiLeaks.
Australia's Foreign Minister, Kevin Rudd, said yesterday: "Mr Assange is not himself responsible for the unauthorised release of 250,000 documents from the US diplomatic communications network. The Americans are responsible for that."
Shiar Youssef, a spokesman for the UK pressure group Corporate Watch, called the withdrawal of corporate support for WikiLeaks "pretty disgusting".
"MasterCard are saying they don't want to be associated with illegal activity and no one has established that this is illegal activity. It's not for a company to say it's illegal, and it's mostly the fuss by the right-wing Americans that has encouraged companies to cut all links with WikiLeaks," he said.
Leaked: Shell and Nigeria
* The oil giant Shell has infiltrated every major ministry in the Nigerian government, according to the latest leaked US diplomatic memos. One of Shell's top executives in Nigeria boasted that her company knew "everything that was being done in those ministries" and that the oil-rich state's leaders had "forgotten" about the the infiltration. The classified communication from the US embassy in Abuja also reveals the company swapped intelligence with the US.
Ironically, the cables, from 2009, reveal that Ann Pickard, then Shell's vice-president for sub-Saharan Africa, thought twice about sharing the information with the US because she considered the US government "leaky".
Hackers crashed the card giant's UK and global websites by bombarding them with requests for information, a technique known as dedicated denial-of-service attacks. "We are working to restore normal service levels," MasterCard said in a statement, adding there was "no impact" on cardholders' ability to use their cards.
After withdrawing the payment of donations to WikiLeaks, PayPal was subjected to a dedicated denial-of-service attack on Monday. The Anonymous group said the attacks could return, saying it was targeting PayPal "in a few hours".
Along with MasterCard, Visa Europe – the US giant's European operation – has severed ties with WikiLeaks. Visa experienced no problems from "Operation Payback".
The social networking site has been abuzz with messages about the WikiLeaks files, but according to Anonymous it has understated the degree of online chatter, thus lowering its profile to other online users. "You're next for censoring #Wikileaks discussion," one blogger warned. Twitter denies interfering with the discussion.