Tue, Nov 29 2005 6:21
Is Your Printer Spying On You?
Color laser printers sure are nifty, but they might be a little
more nifty than you bargained for because certain printers made by
manufacturers such as Canon, Epson, HP, Lexmark, Xerox, and others
place tracking dots on every document you print. Why are they there?
Ask the U.S. Secret Service.
DIGITAL MISCELLANEA - SmartComputing
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Filed under: News
Manufacturers place the dots on
printed documents as part of a deal with the Secret Service, which the
EFF (Electronic Frontier Foundation) says is ostensibly to catch
counterfeiters. Although this practice hasn’t always been a secret, the
information that’s placed on the documents was unknown until the EFF
recently conducted research to break the code that’s used in at least
one of the printers.
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, says EFF Staff
Technologist Seth David Schoen.
According to the EFF, you
won’t even notice the dots unless you look at a printed page with a
blue light and a magnifying glass or microscope. The yellow dots are
less than 1 millimeter in diameter and usually repeat over each page of
It shows how the government and private industry
make backroom deals to weaken our privacy by compromising everyday
equipment like printers, says EFF Senior Staff Attorney Lee Tien.