Hackers who have hit the websites of the CIA, US Senate, Sony and others during a month-long rampage claim to have knocked the site of Britain's Serious Organised Crime Agency (SOCA). Computer security firm Sophos said the SOCA website was sporadically inaccessible yesterday following attack by the hacker group known as Lulz Security. Sophos said it appeared to be a distributed-denial-of-service (DDoS) attack, in which a website is overwhelmed with traffic and becomes sluggish or unresponsive. Lulz Security knocked the CIA's public website out of commission for about two hours last week using a DDoS attack, and also hacked into the US Senate's public website. The group has also released tens of thousands of user names and passwords stolen from Sony and other sites.