<!-- embedding script -->
'Coldblood', a member of the group Anonymous, tells Jane Wakefield why he views its attacks on Visa and Mastercard as defence of Wikileaks.
<!-- END - caption -->A group of pro-Wikileaks activists who coordinated a series of web attacks have explained their actions.
The Anonymous group said they were not hackers but "average internet citizens" who felt motivated to act because of perceived injustices against Wikileaks.
The group said it had no interest in stealing credit card details or attacking critical infrastructure.
The details were posted online by one of the many factions claiming to carry out the attacks.
"Anonymous is not a group, but rather an internet gathering," it said in a statement published on 10 December.
It said the ongoing attacks were a "symbolic action" targeted at corporate website that had withdrawn services from Wikileaks.
"We do not want to steal your personal information or credit card numbers. We also do not seek to attack critical infrastructure of companies such as Mastercard, Visa, PayPal or Amazon," it read.
The statement comes as other documents have come to light suggesting the group may be changing its tactics.
Numbers gameThe statement was published by one of the several Anonymous groups operating online.
"Anonymous has a very loose and decentralized command structure that operates on ideas rather than directives," it said.
Is taking part in these attacks illegal?
<!-- pullout-items--> <!-- Embedding the audio player --> <!-- This is the embedded player component -->
<!-- embedding script -->
The short answer is yes, according to Struan Robertson, legal director at law firm Pinsent Masons.
He told the BBC that in the UK, taking part in the attacks would be a breach of the Computer Misuse Act.
He said that anyone found guilty of taking part could face "up to ten years imprisonment".
"Even downloading the [software] tools to assist in committing these attacks… are themselves guilty of an offence," he said.
He said this could carry a sentence of up to two years in the UK.
Different countries will have different laws and penalties.
However, security expert Peter Wood said that in practice it would be very difficult to track down the people involved because the attacks used "anonymising software" to hid their tracks online.
<!-- pullout-links-->It also acknowledged that there was "perceived dissent between individuals" in the group, but said that it did not threaten its structure.
For example, members have distanced themselves from a member of the group, calling himself Coldblood, who spoke with several media outlets, including the BBC.
Several Twitter accounts have also appeared that claim to be coordinating Operation Payback, as the attacks are known.
Anonymous has been conducting the attacks using a tool called LOIC that allows people to bombard a site of their choosing with data.
The tool launches what is known as a distributed denial of service (DDoS) attack, which tries to knock a website offline by bombarding it with so much data that it cannot respond.
The LOIC tool has been downloaded more than 46,000 times.
However, the group has not always had the numbers needed to make its operations successful.
On 9 December, for example, the group abandoned an attack on the online retailer Amazon after some elements admitted it did not have enough people using the tool.
"While it is indeed possible that Anonymous may not have been able to take Amazon.com down in a DDoS attack, this is not the only reason the attack never occurred," read the document.
"After the attack was so advertised in the media, we felt that it would affect people such as consumers in a negative way and make them feel threatened by Anonymous. Simply put, attacking a major online retailer when people are buying presents for their loved ones would be in bad taste."
Instead, the attack was re-directed towards Paypal and its computer systems, which, according to a status page, have intermittently suffered "performance issues" ever since.
Early on 10 December, elements of the group also attacked money transfer site Moneybookers, knocking it offline briefly at 1100 GMT.
Criminal chainDefences against the attacks are being drawn up as security firms scrutinise the code behind LOIC to work out how attacks happen. Some suggest that well-written firewall rules would be able to filter out most of the harmful traffic.
Information is also starting to emerge about the other resources that supporters of Anonymous have been able to bring to bear. Research by security firm Panda suggests that some of the earlier attacks on payment firms were aided by hi-tech criminals.
What is Anonymous?
<!-- pullout-items--> <!-- pullout-body-->'Anonymous' describes itself as an 'internet gathering'. The term is used to describe a leaderless collective of people who come together online, commonly to stage a protest.
The groups vary in size and make-up depending on the cause. Members often identify themselves in web videos by wearing the Guy Fawkes masks popularised by the book and film V for Vendetta.
Its protests often take the form of disrupting websites and services.
Its use of the term Anonymous comes from a series of websites frequented by members, such as the anarchic image board 4Chan.
These allow users to post without having to register or provide a name. As a result, their comments are tagged "Anonymous".
In the past, groups have staged high-profile protests against plans by the Australian government to filter the internet and the Church of Scientology.
The latter spilled over into the real world with protests by masked members outside churches. An offshoot of Anonymous called Project Chanology focuses purely on this cause.
Many Anonymous protests tackle issues of free speech and preserving the openness of the net.
<!-- pullout-links-->Luis Corrons, technical director of Panda Labs, said during its investigation of Anonymous' attacks its analysts got talking to some of the activists via Internet Relay Chat (IRC).
One of those activists said he had a botnet of 30,000 machines under his control that he was planning to use on behalf of Wikileaks.
"The guy said he had this botnet which was nothing special and was not specifically designed to do these attacks but could be used to do them," said Mr Corrons.
A botnet is a network of hijacked home computers that have been compromised by their owners visiting a booby-trapped webpage that installs code to hand over control to a hi-tech criminal.
Mr Corrons said a botnet with 30,000 machines in it was "about average size". Most of the spam sent around the net is funnelled through machines that are in botnets.
It was becoming clear, he said, that some attacks were aided by the 30,000 machines under the cyber criminals control.
"We know for sure the botnet was used in at least one attack on Paypal," he said.
Panda itself has come under attack with its blog knocked offline for hours by an attack very similar to those Anonymous has been carrying out. Mr Corrons said that, so far, it did not why it was being attacked or who was attacking it.
Fresh leaksThere are also suggestions that the Anonymous group might be about to drop the web attacks in favour of another tactic.
A message posted on the 4chan image board, out of which Anonymous has grown, suggests dropping LOIC in favour of publicising information in the diplomatic cables that Wikileaks is releasing.
Searching for the less-well publicised cables and spreading the information they contain around the web could be more effective than simply knocking out sites deemed to be enemies of Wikileaks, it said.
The message also suggests using misleading tags on posts and YouTube videos to trick people into reading or viewing the information.
"They don't fear the LOIC, they fear exposure," read the message.
It is not yet clear if the call to change tactics has been taken up by the Anonymous group at large.
In related news, Wikileaks looks set to have a rival as former staffers of the whistle-blowing website prepare to launch. Set up by Daniel Domscheit-Berg, Open Leaks is expected to launch in mid_December and will host and post information leaked to it.
<!-- embedding script -->
Posts
Are you a Mastercard customer? Have you been affected by the attack? Send us your comments using the form below.