MasterCard.com has been down since about 5 a.m. ET.
Earlier this week, MasterCard decided to stop processing payments for the group.
Operation Payback appeared to first report the outage, which has been confirmed throughout the morning by DownForEveryoneOrJustMe.com.
DDOS attacks, also known as a denial of service, were used to take down WikiLeaks.org, and forced it to move to WikiLeaks.ch.
This also follows Operation:Paybacks previous attack on a Swiss Bank PostFinance, that had frozen Julian Assange’s accounts.
So far, no one is clear under what law Paypal, Mastercard, PostFinance etc. have closed Julien’s account. Paypal’s Platform VC has however confirmed that they closed the Paypal account of Wikileaks after an intervention from the US State Department.
In a further development, Iceland-based IT firm Datacell said it would move immediately to try to force Mastercard and Visa to resume allowing payments to the whistle-blowing website – stating that such moves could harm its own business.