Operation Payback, a series of co-ordinated attacks by online activists who support embattled WikiLeaks founder Julian Assange, have taken the websites of MasterCard and the Swedish prosecution authority offline. MasterCard was targeted after it announced it would no longer process donations to WikiLeaks. MasterCard maintains that its security has not been compromised. Other sites, such as Visa, Amazon, and Swiss bank PostFinance, have also said they will not allow donations to WikiLeaks. For its part, Operation Payback has vowed to take down any commercial enterprise that censures WikiLeaks.