The Canadian dating website AshleyMadison has been attacked by hackers who have threatened to leak the details of around 37 million customers.
A group calling themselves “The Impact Team” claim to have access to client credit card information and nude photos.
Ashley Madison has since said it has secured the site.
The company, which uses the slogan “Life is short. Have an affair,” has been planning to raise $200 million through an initial public offering on the London Stock Exchange.
The attack comes two months after dating site Adult FriendFinder was breached.