http://blogs.chron.com/techblog/



Identifying code found in laser-printed documents
Here's one to raise paranoia levels everywhere: The U.S. Government has worked with some manufacturers of laser printers to imbed what amounts to an ID code in each printed page.

The Electronic Frontier Foundation discovered the code and broke it:

The U.S. Secret Service admitted that the tracking information is part of a deal struck with selected color laser printer manufacturers, ostensibly to identify counterfeiters. However, the nature of the private information encoded in each document was not previously known.

"We've found that the dots from at least one line of printers encode the date and time your document was printed, as well as the serial number of the printer," said EFF Staff Technologist Seth David Schoen.


You can see the dots on color prints from machines made by Xerox, Canon, and other manufacturers (for a list of the printers we investigated so far, see: http://www.eff.org/Privacy/printers/list.php). The dots are yellow, less than one millimeter in diameter, and are typically repeated over each page of a document. In order to see the pattern, you need a blue light, a magnifying glass, or a microscope (for instructions on how to see the dots, see: http://www.eff.org/Privacy/printers/docucolor/).

This has disturbing implications for those who think paper = anonymity.

"Underground democracy movements that produce political or religious pamphlets and flyers, like the Russian samizdat of the 1980s, will always need the anonymity of simple paper documents, but this technology makes it easier for governments to find dissenters," said EFF Senior Staff Attorney Lee Tien. "Even worse, it shows how the government and private industry make backroom deals to weaken our privacy by compromising everyday equipment like printers. The logical next question is: what other deals have been or are being made to ensure that our technology rats on us?"