An adult dating site has been hacked and almost four million of its members' details have been shared online.
The personal data comes from FriendFinder Networks and its AdultFriendFinder site. The leak and posting online was reported by Channel 4 news, which said that the details of 3.9 million former and current members have been compromised.
The files were posted by a hacker called 'ROR[RG]', according to the report, and FriendFinder Networks confirmed to Channel 4 that it is working with the necessary authorities and security forensics companies.
The company explained that it "understands and fully appreciates the seriousness of the issue".
"We have already begun working closely with law enforcement and have launched a comprehensive investigation with the help of leading third-party forensics experts," the firm added.
"We pledge to take the appropriate steps needed to protect our customers if they are affected."
However, it appears that the firm already knew of the threat, and that the hacker released the haul only after a blackmail demand was not met.
A blog post on the Teksecurity website from April said that the files were on the dark web, along with a note saying that ROR[RG] claimed to be owed money by the firm and was seeking $100,000 in reparation.
"The files included more than enough data to enable a cyber criminal to conduct a massive phishing campaign," said the post.
The files are still online, according to Twitter commentators, and provide a collection of information about members, including home address and sexual preference.
Veteran security blogger Graham Cluley criticised the site, which he joined for research purposes, for not declaring the problem to its members,
"If you're a member of AdultFriendFinder I hope you find the statement AdultFriendFinder offered the media reassuring, and that you'll sleep peacefully in your bed tonight rather than finding yourself all hot and bothered," he said.
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