The hack, first reported on by British outlet Channel 4 News last week, reportedly resulted in the information of nearly 4 million members of Adult Friend Finder leaking onto an online forum frequented by hackers.
In addition to sexual orientation, the data allegedly revealed included e-mail addresses, usernames, dates of birth, postal codes, the unique Internet addresses associated with users' computers and whether members were looking for extramarital affairs.
Around 38% of those who are currently single and looking reported using dating websites or apps to meet potential mates.
While adults of all ages can be found on dating sites, it's the millennial generation that tends to dominate the virtual singles scene.
The convenience of online dating has exploded its popularity in recent years.
Looking for your future partner online is no longer thought of as something reserved for only the socially awkward or desperate.Even being revealed as a member of Adult Friend Finder might be embarrassment enough for some: The site is, as its name suggests, "adult" in nature. Penthouse Media Group acquired it along with the rest of its network, which also includes less risque sites aimed at religious and senior daters among others, back in 2007.That was around the same time Adult Friend Finder settled with the Federal Trade Commission for allegedly foisting "sexually explicit online pop-up ads on unwitting consumers" who weren't looking for porn, including children.The company that now runs both Penthouse and Adult Friend Finder, renamed Friend Finder Networks, did not immediately respond to a Washington Post inquiry about the alleged privacy breach.However, a note a posted to the company's Web site said it is investigating the incident -- and has involved the FBI and cybersecurity company Fire Eye.