A group of “hacktivists” who hacked websites in retaliation for cutting off services to whistle-blowing website WikiLeaks warned today they will continue their activities in a campaign to promote free speech on the internet.
The loose-knit group, known as Anonymous, has disrupted sites belonging to finance giants including MasterCard and Visa by bombarding their websites with millions of bogus visits during a campaign called "operation payback".
Their blog post promising to fight any organisation which supports censorship came as WikiLeaks' payment processor, DataCell, said it was preparing to take legal action against the credit card companies over their refusal to process donations.
DataCell chief executive Andreas Fink said in a statement: "It is obvious that Visa is under political pressure to close us down. We strongly believe a world-class company such as Visa should not get involved in politics and just simply do their business where they are good at."
In a blog linked to its Twitter account, Anonymous wrote: "Hello World. We are Anonymous. What you do or do not know about us is irrelevant. We have decided to write to you, the media, and all citizens of the free world at large to inform you of the message, our intentions, potential targets, and our ongoing peaceful campaign for freedom.
"The message is simple: freedom of speech. Anonymous is peacefully campaigning for freedom of speech everywhere in all forms. Freedom of speech for: the internet, for journalism and journalists, and citizens of the world at large. Regardless of what you think or have to say; Anonymous is campaigning for you."
The post continued: "The internet is the last bastion of freedom in this evolving technical world. The internet is capable of connecting us all.
"When we are connected we are strong. When we are strong we have power. When we have power we are able to do the impossible. This is why the government is moving on WikiLeaks. This is what they fear. They fear our power when we unite. Do not forget this."
Anonymous launched a series of so-called distributed denial-of-service (DDoS) attacks against various websites including the credit card companies, PayPal, and the Swedish prosecutor's office, which is acting in the legal case against WikiLeaks founder Julian Assange.
Mr Assange is on remand in London after being arrested and refused bail over sexual offence charges he is facing in Sweden.
John Mueller, PayPal's general counsel, has said WikiLeaks' account will remain restricted but the firm will release all remaining funds to the site's account.
DDoS attacks, illegal in many countries, involve overloading a website with high numbers of requests so it stops working.
Anonymous said it was leading a "peaceful campaign" and denied being a terrorist or vigilante organisation.
The blog post continued: "Anonymous is doing what many successful campaigns have done in the past; a sit-in. It may be hard to comprehend, but a digital sit-in is our most effective method to show that all of us deserve freedom of speech and a free internet.
"Our methods may appear, on the outside, to be cruel to those the entities that we are campaigning against, but remember by supporting censorship they are denying everyone a basic human right."
Fears were raised in the Twitter-sphere last night that the microblogging site might become the next target after the group's account, Anon_Operation, was closed and Anonymous posted a statement claiming: "Twitter you're next for censoring WikiLeaks discussion."
But in a further posting on Anonops, the group said: "We are not hacking Twitter... DON'T WORRY!... All we are saying that they closed our official account and that is not FREE SPEECH!"
Some supporters accuse Twitter of preventing the term "WikiLeaks" appearing on the site's popular trending topics, a claim that Twitter has denied.
As well as DDoS attacks, Anonymous is helping to create hundreds of mirror sites for WikiLeaks, allowing users to continue to access the website's content via a different server.