A group of hackers calling themselves the Lizard Squad has claimed responsibility for knocking down Sony’s Playstation Network (PSN) for the majority of Sunday evening.

Although Sony acknowledged that their PSN servers were down, the company did not make any mention of a possible cyber intrusion. “We are aware of the issues some users are experiencing, and are working to address them,” said Sony’s Playstation Twitter page. Other users of the gaming network reported an error that read: “Page not found. It’s not you. It’s the internet’s fault,” reported PC World.

The Lizard Squad announced that they had breached PSN’s networks roughly two hours before Sony released a statement regarding the issue. The hackers attacked the PSN in August with a distributed denial-of-service (DDOS) assault. A DDOS is a nuisance attack that floods the servers of the target, rendering the sites affected largely inoperably for a certain period of time, but usually causes no long-term harm.

The group’s attacks have not just been reserved for Sony. On Friday, they turned their focus on competitor Xbox Live, attacking their network. “this entire month will be entertaining,” threatened the Lizard Squad.

The swath of attacks against gaming networks comes just days after an unprecedented cyber intrusion occurred against Sony at the hands of a hacker group calling themselves Guardians of Peace (GOP). Some Cybersecurity experts and law enforcement officials believe that the attack fits a pattern that most-closely resembles one that is carried out by North Korea. After infiltrating Sony’s computer systems, the hackers released the personal information of almost 50,000 people.