Gay people who used the dating site could face the death penalty in some countries after their details were exposed by hackers.
People living under oppressive regimes who used the Ashley Madison adultery dating site to arrange secret liaisons could be at risk of prison or the death penalty.
The hacking of the site has exposed millions of people, including hundreds in Saudi Arabia where adultery is potentially punishable by death.
The site was predominantly used by people looking to cheat on their partner, but it is thought that many single gay people used the service to avoid detection by oppressive governments.
Homosexuality is punishable by death in Saudi Arabia, while in Qatar - where 50 members of the site are registered - it carries a 5-year prison sentence.
Sky's Technology Correspondent Tom Cheshire said one Reddit user based in Saudi Arabia has even fled the country after being exposed.
He said: "Ashley Madison was sold as a way to get casual hook-ups for cheating spouses, but some users in the Middle East say they used it as a discreet way of having meetings with homosexual men who didn't want to be identified.
"There are 1,200 email addresses with the Saudi Arabia suffix where homosexuals face the death penalty.
"More than 50 accounts are from Qatar where homosexual relationships are punishable by 5 years in prison.
"And there are 1,500 from Turkey where homosexuality isn't illegal but you can get kicked out of the country or banned from military services."
Details of the site's 37 million members were obtained by hackers in July, who demanded that the site be shut down.
This week, with the site still online, they released the data on the dark web.
Among those exposed are civil servants, senior military officers and university professors.
Source: Sky News, August 21, 2015
