Websites operated by MasterCard, PayPal, Post Finance and Visa all experienced degraded services for a time yesterday, and top domain names may still be receiving denial of service attacks as protesters respond to the coordinated withdrawal of services to Wikileaks by a line-up of major US companies.
Non-payments services have also been interrupted, including web-hosting. Facebook and Twitter have also walled off content related to advice on how to cooperate in the attack, which is receiving publicity as part of the wider reporting on Wikileaks.
PayPal might be the most at risk from denial of service attacks since access to paypal.com is vital to much of its payments traffic.
For Visa and MasterCard it is merely an inconvenience, since neither, amusingly, features an actual payment option anywhere important on their websites.
PayPal contested suggestions - made by one of its own executives at a conference in France this week - that the freeze on Wikileak's account was the result of a government edict.
"PayPal was not contacted by any government organization in the US or abroad," general counsel John Muller wrote, in a posting on the
PayPal blog last night.
Muller wrote that PayPal froze Wikileaks account for a time in 2008 and in 2009. He added that the latest freeze followed a review this week.
This review came "after the US Department of State publicized a letter to WikiLeaks, on November 27, stating that WikiLeaks may be in possession of documents that were provided in violation of US law," he wrote.
"PayPal's Acceptable Use Policy states that we do not allow any organization to use our service if it encourages, promotes, facilitates or instructs others to engage in illegal activity."
DataCell EHF, a firm based in Iceland which facilitates credit card-based donations to WikiLeaks, said it will sue Visa Europe and MasterCard over the freeze.
The Sydney Morning Herald's reports last night and this morning seemed comprehensive in a crowded field, and cover the involvement by activists in Australia central to the denial of service attacks.
The Register also has detailed reports, among an avalanche of media reports on the topic.