The timing makes the rather strong suggestion that this action was in response to Mastercard cutting off WikiLeaks' funding on Monday this week.
In fact, The Guardian wrote the following in its article:
The action was confirmed on Twitter at 9.39am by user @Anon_Operation, who later tweeted: "WE ARE GLAD TO TELL YOU THAT http://www.mastercard.com/ is DOWN AND IT'S CONFIRMED! #ddos #wikileaks Operation:Payback(is a bitch!) #PAYBACK"
Hackers reportedly used a distributed denial-of-service attack (DDoS), which is designed to flood web servers with so many requests it slows its service to a virtual stand-still - very much like a traffic jam on a major city artery.
The sad thing is that many innocent MasterCard users were probably affected, feeling the pain if they were trying to access the website. In addition, MasterCard has confirmed that its SecureCode service is also disrupted, which would be very serious as it could impact transaction processing.
Swiss bank Post Finance is reported to have also suffered a similar attack, and the hacker group claim to be eyeballing PayPal, promising they will be targeted soon. The group are linked in several reports to 4Chan, the popular internet messageboard.
As financial services run for the hills in an attempt to distance themselves from servicing WikiLeaks, we seem to be nearing unprecedented makings of a cyber war. On one side, you have the freedom of speech argument; on the other, the leaking of sensitive information putting third-parties at risk.
Adding fuel to the fire was WikiLeaks' founder Julian Assange's arrest yesterday for alleged sex crimes committed in Sweden. UK Judge Howard Riddle denied Assange bail, and he now awaits his extradition trial next week on 14 December.
You better buckle in tightly as I think we can all agree that this is far from over.
As we await the next news headline, we'd love to hear your thoughts: if you had to point the finger at one party who is most to blame for this mess, who is it: WikiLeaks? Those named and shamed in the leaked documents? Financial services for cutting WikiLeaks off? The hackers? Founder Julian Assange?