Operation Payback has claimed yet more scalps overnight as distributed denial of service (DDoS) attacks took down both Visa’s and Sarah Palin’s websites.
The campaign is currently targeting PayPal’s API, and it has been suggested that Mastercard could be next.
Orchestrated by hacktivist group Anonymous, Operation Payback is an ongoing campaign against organisations deemed by the group to be against piracy or free speech.
In a statement, the group said that Operation Payback “is now directed towards those who employ unfair means to fight WikiLeaks.”
According to Anonymous, Operation Payback targets “morally corrupt” organisations like Mastercard and Visa, which have attacked “WikiLeaks’ supply lines in the ongoing War for Freedom of Information.”
He said: "The campaign is not over, it's still going strong. More and more people are joining.”
"I see this as becoming a war - but not a traditional war: this is a war of data,” he added.