Hacking group DerpTrolling has published what it claims to be the usernames and passwords of thousands of PlayStation Network, Windows Live and 2K Games accounts.
The publicly available Pastebin document is said to contain the data of 2,131 PSN accounts, 1,473 Windows Live Accounts and 2,000 2K Games accounts.
IBTimes UK has attempted to verify the validity of the accounts, testing numerous username and password combinations, but none have worked.
"Dear Internet," reads the Pastebin document, "The following is a very small portion of Lord Gaben and the rest of his crew's glorious raids across the high seas of the Internet."
The group has also claimed responsibility for last week's distributed denial of service (DDoS) attack on Blizzard's World of Warcraft servers following the release of expansion pack Warlords of Draenor.
The move follows a CNET interview in October with a member of DerpTrolling, in which the anonymous hacker claimed the group was in possession of "around 7 million usernames and passwords".
"We have around 2 million Comcast accounts, 620,000 Twitter accounts, 1.2 million credentials belonging to the CIA domain, 200,000 Windows Live accounts, 3 million Facebook, 1.7 million EA origins accounts, etc," said the member.
Today's alleged leak comes despite the member saying in that interview that "DerpTrolling in no way wants to harm our children by leaking such damaging data".
"There are a lot of people and fellow hackers who believe that DerpTrolling is just a bunch of kids," he continued. "But the truth is we have been associated with and assisted every well-known hacking group aside from The Syrian Electronic Army and LizardSquad (although we were invited to join LizardSquad)."
DerpTrolling's aim is to force companies to improve their security against such hacks and attacks.
IBTimes UK has contacted Microsoft, Sony and 2K for comment on the alleged leak.