Last week, a group of hackers released the stolen data of Ashley Madison users, a website used by people who are looking to start an extramarital affair. The user data included names, street addresses, email addresses and data on credit card payments going all the way back to 2007.

After wading through the data, the Associated Press found that at least 1,500 federal employees have been using the site.

“We were a little reluctant to take at face value the list of [Ashley Madison] subscribers,” says Ted Bridis, the news editor for the Washington investigative team at the Associated Press. “Anyone could create an account using any name or email address, so we dove deeper into the data. We noticed that Ashley Madison had recorded the incoming computer internet address — the IP address — for every subscriber who made a credit card transaction.”

The AP compared the IP addresses of Ashley Madison users with known federal IP addresses. From there, the reporters were able to identify specific federal workers who were paying for the service and connecting to the site — sometimes from their office computers. Birdis says that the credit card transactions sometimes revealed multiple months of payments to the site.

“The AP review was specifically intended to discover and identify people who may be susceptible to extortion or blackmail based on [their] sensitive national security jobs,” he says. “We found a number of them: Two assistant US attorneys; an IT administrator inside the White House; a Justice Department division chief; a government hacker at the Homeland Security Department; a scientist at National Nuclear Laboratories; and a number of foreign diplomats at the State Department.”

The users attempted to conceal their identities by using email addresses that were not associated with their government positions — some also went by usernames like “SexlessMarriage,” “SoonToBeSingle” and “LatinLovers,” among others.

“Some Justice Department employees we noticed appeared to be using prepaid credit cards to try and preserve their anonymity,” Birdis says. “But since they were connecting to the service from inside the DOJ offices, we were able to walk that connection right back. I don’t think the government realized that it could do the type of analysis that we have done, but we’ve already heard that some agencies are beginning a review process to consider whether clearances ought to be revoked or modified.”

This story first aired as an interview on PRI's The Takeaway, a public radio program that invites you to be part of the American conversation.