EFF Decodes Color Laser Printers’ Yellow Dots

The Electronic Frontier Foundation has decoded the 2-D array of yellow dots added to white areas of pages by color laser printers:

<blockquote><p>A research team led by the Electronic Frontier Foundation (EFF) recently broke the code behind tiny tracking dots that some color laser printers secretly hide in every document.</p>
<p>“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.</p>
<p>“Underground democracy movements that produce political or religious pamphlets and flyers, … 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. “… The logical next question is: what other deals have been or are being made to ensure that our technology rats on us?”</p></blockquote>
<p>The Washington Post has <a href="http://www.washingtonpost.com/wp-dyn/content/article/2005/10/18/AR2005101801663.html">a story</a> with more background information.