If you read the full article you'll see its not just from database dumps.
"No domains were found for your email address. Whilst your email address was found in a stealer log, no websites were found alongside it. This can be due to the way the log was formatted."
TL;DR: You could try my email in there, believe credentials were stolen, when that might be recycled leak stuffing.
Stop reading Ars and your name will be cleared. This isnt real journalism, it is Ars-washed political talking points.
If you had to work in the nightmare of secure systems, the computers are literally in a different room, there is no Internet access in there, and you can’t take your smartphone in there.