http://www.news24.com/News24/Technol...819331,00.html

Excerpt:

Secret code 'traces copies'
19/10/2005 12:37 - (SA)


San Francisco - A secret code embedded in many colour laser jet printers allows the US government and any other organisation capable of reading the cipher to identify when the copies were made and on which particular machine, according to research conducted by the Electronic Frontier Foundation (EFF).

The San Francisco-based privacy organisation said it had detected almost invisible patterns of yellow dots on every document printed on the affected machines that could indicate when and where the print was made.

Among the copiers found to include the secret yellow dots are ones made by Brother, Canon, Dell, Epson, HP, Konica/Minolta, Kyocera, Lexmark, Ricoh, Tektronix/Toshiba and Xerox.

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