Laser Printer Fingerprints

Tech Smores! reported The EFF has broken the tracking code for the Xerox DocuColor. The DocuColor prints a faint 15x8 grid of yellow dots on every page. To see these dots you need a magnifying glass. You can also use a blue light to make the dots appear black. The EFF page has a built in application for decoding the dots which hide the time, date, and serial number of the printer. The EFF also maintains a list of printers which do or don’t have this "feature". More information is here

This is interesting. I have known for a long time that these yellow dots were there, but I did not know until now how to interpret them.