“Unfortunately for PlayStation Network and Qriocity services users, it looks like the widespread network outages will continue.
Since Sony’s PlayStation and music networks went down two days ago, there has been a fair amount of public speculation over the cause of the outage. (Largely due to Sony’s tight-lipped handling of public relations.) Many blamed vengeful gremlins loose in Sony’s server clusters and datacenters, while others immediately pointed the finger at Anonymous, the merry band of hackers that metastasized out of 4chan.”
Source: Hack Attack: Sony Confirms PlayStation Network Outage Caused By ‘External Intrusion’