Hours after The Intercept dropped a leaked report detailing Russian efforts to hack the 2016 election, federal government investigators announced the arrest of the suspected leaker, 25-year-old NSA employee Reality Leigh Winner. According to a Department of Justice affidavit, Winner left a trail of physical and digital evidence identifying her as the leaker.
After reading the affidavit, Ted Han, director of technology at DocumentCloud, became curious about what incriminating information could have been hidden in the document. Zooming in on the PDF, he found what he was looking for — tiny yellow dots on the pages.“Microdots basically provide a smoking gun,” Han said. “It sure makes it really easy to look up specifically what print job that document came from.” The pattern of dots, when looked up through a guide posted by the Electronic Frontier Foundation, reveal the exact date, time, and printer of the document