So far, though, it isn't easy to find the exposed cheaters online.
Adult Friend Finder, which boasts 64 million members, claims to have "helped millions of people find traditional partners, swinger groups, threesomes, and a variety of other alternative partners." Included in the exposed personal information are customers' email addresses, usernames, passwords, birthdays and zip codes, in addition to their sexual preferences.
With an estimated 1,000 online dating sites in existence, it can be hard to sift through all the options and decide which is the best site.
Being able to know how to evaluate a dating site is essential in the decision process, and it will bring you that much closer to finding a good match.
We are working with law enforcement agencies, which are investigating this criminal act." Ashley Madison is a dating website, with one important twist: Instead of connecting eligible singles, it caters to married people interested in having an affair.
The site claims to have 37 million members, and has in the past bragged about its data security. After all, its databases have enormous potential for use in blackmail schemes.
The hackers -- or hacker, perhaps -- appear to be upset over the company's "full delete" service, which promises to completely erase a user's profile, and all associated data, for a fee.
"Full Delete netted [Avid Life Media] .7 million in revenue in 2014.
It's also a complete lie," the hackers were quoted as saying in a manifesto published by Krebs.
"Users almost always pay with credit card; their purchase details are not removed as promised, and include real names and address, which is of course the most important information the users want removed." On Monday afternoon, the company defended the service, and also said it would make it free.
Avid Life Media also said that it had hired "one of the world's top IT security teams" to work on the breach.
The hack follows a similar event in March, when more than 3.5 million people's sexual preferences, fetishes and secrets were exposed after dating site Adult Friend Finder was hacked.