Some colour laser printers are printing an invisible grid of yellow dots on all printouts. These yellow dots store the serial number of the printer and time stamp of the printed page.

A website has been setup called seeingyellow.com by members of MIT Media Labs’ Computing Culture research group which is built to protest against the watermarks produced which is clearly a violation of civil liberties of laser printer users.

The yellow-dot “watermark” allows the US Secret Service to enlist the help of the manufacturers in tracking counterfeit currency generated on laser printers. A statement on seeing yellow.com calls this practice a “direct attack on the privacy of the owners and users of printers, and in particular, on their right to free, anonymous speech.”

A decoder is available on Electronic Frontier Foundation for the Xerox DocuColor colour laser printout. It states the process of reading the date, time, and printer serial number from forensic tracking codes.

Printer manufacturers like HP, Brother and others have been following this practice in the laser printer industry. There have been no reports of countries in the European Union following a similar practice.

via Dr.Dobb’s