Your Printer Tells All
I thought this was fairly well known but the reaction to yesterdays printer comments have ranged from “Wow, I didn’t know that” to “Are you that paranoid?” PC World actually reported this in 2004.
Most world governments require copier and printer manufacturers to include a method to track where a printed image came from. Originally, it was designed to trace counterfeits but now the explanation is mostly related to terrorism. The only publicly disclosed technique at this time was created at Xerox in the 80’s and consists of a yellow pattern of microscopic dots.
Close up of actual tracking dots, as seen through a microscope.
The information available is said to include the printer serial number as well as the date and time the image was printed. The Electronic Frontier Foundation is investigating and has published a list of those printers they’ve been able to identify as using the yellow dot technique. So far, their list is limited to laser printers using the Xerox method. Any technique used by ink jet printers has not been disclosed to the public.
Exposed using a Photon blue LED light
Photos from www.eff.org