HACKERS have claimed attacks on the websites of Visa, Mastercard and Sarah Palin in revenge for their stances on whistleblowing website WikiLeaks.
Organisers of the group "Anonymous" said thousands of hackers had joined their effort to defend the site and its founder Julian Assange, and vowed to extend their campaign to anyone with an "anti-WikiLeaks agenda."
WikiLeaks said it had nothing to do with the hacking, which mainly targeted financial institutions that had cut off funding for the whistleblowing website.
The site of credit card giant Visa was hit this morning after by members of the hackers group "Anonymous" and was still down two hours later.
Visa.com went down as members of Anonymous launched a coordinated cyber attack announced on their Twitter feed Anon-Operation.
"Operation Payback. TARGET: WWW.VISA.COM :: FIRE FIRE FIRE!!! WEAPONS," the message said.
She has described Mr Assange as “an anti-American operative with blood on his hands” and asked “Why was he not pursued with the same urgency we pursue al-Qa'ida and Taliban leaders?”
Mr Carroll said the Palin website went down for about six minutes.
According to ABC News, besides attacking the Palin website, the hackers also “disrupted” the personal credit card accounts of Ms Palin and her husband, Todd.
“No wonder others are keeping silent about Assange's antics,” ABC News quoted Ms Palin as saying in an email.
“This is what happens when you exercise the First Amendment and speak against his sick, un-American espionage efforts.”
Mr Carroll said Anonymous members also briefly took down the website of senator Joe Lieberman, who issued an early call for US companies to withdraw their technical support from WikiLeaks, an appeal which has been widely followed.
Credit card sales were disrupted yesterday when hackers disabled the main mastercard.com site for about seven hours.
Mastercard initially denied that cardholders would be affected. However it later released an automated technical notice warning of a failure in its 3-D Securecode system, an authentication service for online payments.
"Customers may still be experiencing intermittent connectivity issues," the notice said. Mastercard said it was restoring full service and cardholders' data was not at risk.
Securecode is used by many of the biggest online retailers preparing for Christmas, including Amazon.co.uk.
"With the Secure system down many online retailers will not accept payment from Mastercard," said Ian Cushion of Secure Trading, an online transaction company. "It failed at about 9.30am. I'd guess hundreds of customers were affected, at least."
Anonymous has also taken offline the websites of the Swedish prosecutors' office, which wants to question Mr Assange, and Postfinance, the Swiss bank that froze Mr Assange's account last week. Each was swamped by the volume of queries.
An Anonymous statement released earlier today (Thursday) on Twitter simply read: "We will fire at anyone or anything that tries to censor WikiLeaks. The major s***storm has begun."
Mr Assange spent his first full day in a London prison after he was refused bail yesterday. But Wikileaks is continuing its publication of a wave of US diplomatic cables, enraging governments around the world.
After WikiLeaks appealed for donations to be able to continue its activities, Mastercard and Visa said they were suspending payments to the site, sparking attempts to hack into the payment services.
In an online chat with AFP, organisers of Anonymous said about 4000 hackers had thrown their weight behind the group's efforts in response to online appeals.
"The current target is Mastercard.com, but anyone that has an anti-Wikileaks agenda is within our scope of attack," they said.
"We recruit through the internet, that means, everywhere: imageboards, forums, Facebook, Twitter... you name it, we're using it," they said, adding that members were drawn from "all over the world."
WikiLeaks spokesman Kristinn Hrafnsson told AFP the hackers were "not associated" with his organisation.
"We are not associated with them and this is a decision that they are taking. It is part of a consumers' response, I gather," he said.
In another twist to the cyber war, Icelandic firm DataCell said it would sue Visa for blocking payments to WikiLeaks and accused the credit card giant of bowing to political pressure.
AFP, The Times