Sony on Wednesday responded to a congressional inquiry regarding major cyberattacks against its Qriocity, PlayStation Network, and Sony Online Entertainment businesses that leaked loads of personal information, including credit card numbers, to hackers. The hackers were able to breach Sony’s security while another group, dubbed “Anonymous” mobbed its servers with denial-of-service (DoS) attacks. “Whether those who participated in the denial of services attacks were conspirators or whether they were simply duped into providing cover for a very clever thief, we may never know,” Sony said in its letter to Congress, noting that it still has no idea who hacked its systems. A total of 101 million accounts across Sony’s multiple networks were compromised as Sony became the “victim of a very carefully planned, very professional, highly sophisticated criminal cyberattack designed to steal personal and credit card information for illegal purposes,” the company said. According to The Wall Street Journal, 12.3 million credit card numbers were stolen, 5.6 million of which belonged to users in the United States. So far Sony has not confirmed that the credit card numbers have been used illegally. The firm hopes to get its gaming networks back online as soon as possible.