EFF research into hidden codes colour prints
The US based digital rights organisation EFF has started extensive research into the hidden codes some laser colour printers and photo copiers add to every page they print or copy. In 2004 printer-manufacturer Canon was awarded a Big Brother Award in Germany for secretly adding a unique code to every print-out. Soon after, it turned out the practice is very wide-spread.
The unique number on every print-out is invisible to the bare eye, measuring only 0,1 millimetre. After the Big Brother Award for Canon, the Dutch police immediately admitted they use the codes to detect the sources of print-outs, tracing individual printers through the vendor chain. Questioned by the Lower House, the Dutch minister of Economical Affairs said he agreed manufacturers should inform their customers, but did not create any obligation in that direction.
EFF suspects the US government of having persuaded most manufacturers of including the secret codes, "in a purported effort to identify counterfeiters." In addition to a call to the public to send in print-outs, to create an even more extensive list of printers, EFF has filed a Freedom of Information Act (FOIA) request to find out all about "the Secret Service’s efforts to promote the development and implementation of machine identification code (MIC) technology in colour laser printers and colour photocopiers."
EFF: Is Your Printer Spying On You? (13.10.2005)
EDRI-gram 'Secret code added to most colour prints' (03.11.2004)