Anonymous compromises MasterCard accounts?

Fighting for WikiLeaks and founder Julian Assange, online collective attacks Visa and MasterCard

[Updated at 15:15 PST Dec 8: Operation Payback's Twitter account has been deleted.]

Both of the main websites for Visa and MasterCard suffered hours-long outages Wednesday as a result of distributed denial of service (DDoS) attacks, and an uncountable number of MasterCard account information (account number with expiration date) has leaked online, if the people behind the attacks are to believed.

Operation Payback is an ongoing campaign by Anonymous, a loosely organized online group of generally tech-savvy individuals, against what it considers major anti-piracy and anti-freedom entities. Anonymous, vocal supporters of Julian Assange and his whistleblower site WikiLeaks, found fault with the decision made by both major payments companies Visa and Mastercard to suspend any and all payments made to the nonprofit organization.

According to the Anonymous website:

"While we don't have much of an affiliation with WikiLeaks, we fight for the same reasons. We want transparency and we counter censorship. The attempts to silence WikiLeaks are long strides closer to a world where we can not say what we think and are unable to express our opinions and ideas."

And now hundreds if not thousands of account numbers and expiration dates have leaked, according to the Operation Payback Twitter account. Mastercard denies that any customer information has been stolen.

MasterCard’s only statements today, in response to the attacks on its website, have been messages of reassurance that no sensitive customer information or financial data has been compromised.

Following Assange’s arrest on Tuesday, a Visa Europe spokesperson said payments to WikiLeaks would be suspended “pending further investigation into the nature of its business and whether it contravenes Visa operating rules." Mastercard did the same just hours earlier, claiming that “rules prohibit customers from directly or indirectly engaging in or facilitating any action that is illegal.”

Previous victims of Operation Payback have been the RIAA in October, for defeating Limewire in a court case over copyright infringement, and Gene Simmons for encouraging musicians and labels to “sue everybody.”

Update 1: The second of the two tweets above was the last, we believe, sent out by the Operation Payback Twitter account on Wednesday before the account was suspended. The link shared in the tweet, when I first clicked it, took me to a simple list of credit card numbers and expiration dates. Minutes later the link redirected to the main page for Pastebin.

Within 10 minutes, the Operation Payback account was no longer accessible. The move came within a couple hours of Facebook's deletion of the Operation Payback Facebook page.

Both Facebook and Twitter decline to comment on specific cases of account suspension.