That data is incredibly revealing and potentially damaging.
Andrew Auernheimer, a controversial computer hacker who looked through the files, used Twitter to publicly identify Adult Friend Finder customers, including a Washington police academy commander, an FAA employee, a California state tax worker and a naval intelligence officer who supposedly tried to cheat on his wife.
Creating online dating profiles helps consumers carefully consider potential matches.
Dating does not include listings for all dating sites.
Most services offer digital messaging, while others provide additional services such as webcasts, online chat, telephone chat (VOIP), and message boards.
Members can constrain their interactions to the online space, or they can arrange a date to meet in person.
Adult Friend Finder asks customers to detail their interests and, based on those criteria, matches people for sexual encounters.
The site, 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." The information Adult Friend Finder collects is extremely personal in nature.