On Monday, news outlet The Intercept released documents on election tampering from an NSA leaker. The documents revealed that a Russian intelligence operation sent spear-phishing emails to more than 100 local election officials days before the election , which ran through a hack of a U.S. voting software supplier. Hours later, the Department of Justice charged 25-year-old government contractor Reality Leigh Winner with sharing top secret material with the media . The DoJ said it Winner had "printed and improperly removed classified intelligence reporting, which contained classified national defense information" before mailing the materials. But how could the DoJ know that it was Winner who had printed the documents, or that the documents were printed at all? ArsTechnica explains:Further reading: How The Intercept Outed Reality Winner