Credit card company Mastercard’s website is currently unavailable due to an apparent hacking campaign organised in response to the company’s refusal to handle donations to the WikiLeaks website.
The attack, called "operation: payback" has apparently been organised by internet freedom of speech activists, calling themselves "Anonymous".
Mastercard announced on Monday it would no longer handle donations to WikiLeaks as the website was engaged in "illegal activity".
A message posted this morning by the Anonymous group on popular micro-blogging site Twitter read: “WE ARE GLAD TO TELL YOU THAT http://www.mastercard.com/ is DOWN AND IT'S CONFIRMED!” and “Operation:Payback(is a bitch!)”.
The Swiss bank that closed WikiLeaks’ founder Julian Assange’s account was the target of a similar attack on Monday. Other companies that have denied services to WikiLeaks include Amazon and Visa.
The Mastercard website is thought to be undergoing a Distributed Denial of Service attack. Such attacks consist of swamping a website with requests, overloading the server and preventing legitimate communication and normal use of the website.
Mastercard have yet to release a statement on the attack and were unavailable for comment this afternoon.
