[UPDATE 2:] Sony has admitted that the PSN hacker stole user data, such as account names, passwords, email addresses and home addresses. Sony also said that credit card numbers may have been stolen during the attack, though the company could not say for sure whether this had occurred or how many were affected.
[UPDATE 1:] Sony finally confirmed on Saturday that the ongoing PlayStation Network outage was caused by "an external intrusion."
From the Sony EU blog:
An external intrusion on our system has affected our PlayStation Network and Qriocity services. In order to conduct a thorough investigation and to verify the smooth and secure operation of our network services going forward, we turned off PlayStation Network & Qriocity services on the evening of Wednesday, April 20th.
Still no word on when service will be restored.
Sony previously said they are working on restoring service to its 70 million users but has not revealed the source of the problem.
Some now believe the outage to be the result of a distributed denial of service attack. Sony's recent brush with hacker-activist collective Anonymous led other to speculate that the group had again targeted the PSN.
Anonymous on Friday addressed these allegations in a release titled, "For Once We Didn't Do It."
"While it could be the case that other Anons have acted by themselves AnonOps was not related to this incident and takes no responsiblity for it," the release read.
According to the post, Sony's EU blog on Friday mentioned "the possibility of targeted behaviour by an outside party." However, Sony appears to have removed the post, as it no longer appears on the EU blog.
No other explanation has been offered at this time.