* Color printers contain embedded patterns that can reveal personal information
* Serial numbers, dates and even the exact time a document was printed can all be found
* Virtually every modern printer uses these trackers, and they’re naked to the human eye
Ever since color printers were introduced in 1988, the government has been using invisible tracking dots embedded in the ink to track you. These hidden trackers are made up of tiny yellow dots that can’t be seen by the human eye. When they’re examined under a certain light, serial numbers, dates and even the exact time a document was printed can all be confirmed–simply checking the dots.
It was these same trackers that were used to identify NSA contractor Reality Winner, who leaked sensitive government data earlier this month. When The Intercept included a scanned copy of the printed documents in their article, FBI agents were able to use the trackers to identify which printer the documents came from, when, where and at what time they were printed. From there, they were able to check the number of people who used the printer that day and narrow the list down to Winner.
This isn’t the first time these hidden trackers have been brought to light. In 2004, a PC World wrote in implicit detail how color printers are used to secretly track documents. Experts believe every color printer uses the trackers, though the way they’re implemented may differ. You can check here for a full list of printers that are believed to include these trackers.