Adultery website AshleyMadison has been hacked by a group that are now threatening to expose the platform's 37 million cheating users unless the website is taken down.
The website, whose tagline is "Life is Short. Have an Affair", is founded on confidentiality and privacy. It facilitates relationships between married people looking to cheat on their spouse. If its users were made public then it's likely that a string of divorces would follow.
The data was stolen from Avid Life Media (ALM), which owns Ashley Madison along with other hookup sites such as Cougar Life and Established Men.
ALM confirmed the hack today by issuing a statement.
In April, ALM claimed AshleyMadison was the second most popular dating site in the world, losing out only to dating giant Match.com. It also claimed to have 1.7 million users in Britain.
The hacking group behind the attack refers to itself as "The Impact Team".
Security blog KerbsOnSecurity said the group has already published a small percentage of the site's user account data online.
When the group published the data, it also released a statement demanding AshleyMadison and Established Men were removed from the internet.
Should ALM fail to do this then the hackers are threatening to reveal the names, addresses and sexual fantasies of the millions of people who have created a profile on AshleyMadison.
ALM said in a statement: "We apologise for this unprovoked and criminal intrusion into our customers' information.
"We have been able to secure our sites, and close the unauthorised access points.
"Any and all parties responsible for this act of cyber-terrorism will be held responsible."
The Impact Team has targeted ALM over its Full Delete feature - a $19 service that allows AshleyMadison users to remove their profile and all accompanying information.
The hacking group claims that ALM doesn't actually delete everything, stating that the user's real name and credit card details remain online.
ALM revealed in April that it planned to float on the London Stock Exchange as it looked to raise money from investors hungry to cash in on the success of dating startups.
The company tried floating in Toronto five years ago, only to be greeted to a lack of appetite among cautious North American investors.
"Europeans have a more laissez-faire attitude toward infidelity," said Christoph Kraemer, head of international relations for AshleyMadison at the time. "Investors here will look past that and at the numbers."
Kassem Younis, a privacy expert and CEO of Thoughts Around Me, an app that lets people share things anonymously about issues affecting their everyday lives, said AshleyMadison has let its users down by failing to protect them.
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