Sony seems to be a victim of hackers once again. A hacker group called "Lizard Squad" has claimed responsibility for attacking Sony's online PlayStation store, which is down on Monday. Visitors to the site are greeted with a message that says "Page Not Found! It's not you. It's the internet's fault".

"Lizard Squad" has posted "PSN Login #offline #LizardSquad" as their Twitter status.

Sony Entertainment Network has responded by tweeting that they are aware of the issues that users are having in connecting to the PlayStation network.

"Thanks for your patience as we investigate," the company tweeted at about midnight GMT.

Sony's Japanese firm's Hollywood film studios' corporate network was also hacked into last month, followed by an online leak of unreleased movies, along with confidential information such as actors' salaries.

Meanwhile, the outage on the PlayStation network follows one on Microsoft Xbox network, which was down for at least a day last week.