Is Your Printer Spying On You?
Media Lab has started a website that helps consumers contact the manufacturer of their printer so they can request that “tracking dots” be eliminated from their machines.the dots hold information about the serial number, make and model of your printer and were placed there at the behest of the Secret Service—supposedly to help locate counterfeiters. Seeing Yellow, a project by MIT’s Media Lab, claims that after contacting the printer manufacturer about how to disable the tracking dots, the Secret Service showed up at one consumer’s door asking questions. Uh, scary.
From Seeing Yellow:
Most color laser printers made and sold today intentionally add invisible information to make it easier to determine where (and when) a particular document was printed. This seems to have been done as part of a secret deal between the United States Secret Service and the individual manufacturers. Some of the manufacturers have mentioned the existence of the tracking information in their documentation, and others haven’t. None of them have explained exactly how it works or what information is conveyed. No law requires printer companies to help track printer users this way, and no law prevents them from stopping this practice or giving customers a solution to avoid being tracked.This information is most famously known to be coded by patterns of yellow dots that the printers add to the background of all the pages they print. The yellow dots are hard to see with the naked eye, but can be seen under bright blue light or with a microscope. Their arrangement reveals which printer was used to print a particular document, and sometimes also shows when it was printed. Some of the codes have been understood while others are still mysterious, but none of the printer manufacturers has denied that the dots are intended to help track a particular document to a particular printer (or that they can actually be used for this purpose). This is a direct attack on the privacy of the owners and users of printers, and in particular, on their right to free, anonymous speech.
Here’s a list of affected printers as well as more info from the EFF.
List of Printers Which Do or Do Not Display Tracking DotsThis is a list in progress of color laser printer models that do or do not print yellow tracking dots on their output.We are in the process of trying to interpret the information conveyed by these dots as part of our Machine Identification Code Technology Project.
Limitations of this information
A “no” simply means that we couldn’t see yellow dots; it does not prove that there is no forensic watermarking present. (For example, the HP Color LaserJET 8500 series does not include any yellow tracking dots that we can see, but it may still include some kind of forensic marking, since the majority of other Color LaserJET models do. Other forensic marking techniques have been invented, and we do not yet know how to determine whether these techniques are used by a particular printer.)A “yes” simply means that we (or another source, as noted) saw yellow dots that appeared anomalous to us. Until we decipher the marking schemes or receive other confirmation, this does not constitute proof that any particular kind of information is represented by these dots. In a very few cases, for example, they might be the result of a dithering technique, rather than a forensic mark, or they could be the result of a poorly calibrated printer. In most cases, we are confident that the arrangement of dots is intentional and is intended to track users.
Sources of information
We have employed three sources of information. We looked at printer output under a blue light and/or a computer microscope; we consulted press reports about printers (e.g. at Druckerchannel); we relied on printer manuals and other manufacturer statements. We welcome additional statements by manufacturers, resellers, or technicians.
Thanks to our friends at software firms and symphonies, public schools and physics labs, semiconductor fabs and ice cream parlors, in about a dozen countries around the world.
Table of printers
Manufacturer Model Dots? Comments
Brother
HL-2700CN yes volunteer test
HL-4200CN yes EFF test
Canon
CLC 1000 yes EFF test
CLC 2400 yes EFF test
CLC 3002 yes EFF test
CLC 4000 yes EFF test
CLC 5000+ yes EFF test
CLC-iR 3200-C1 yes EFF test
Color imageRUNNER C2570 yes EFF test
Color imageRUNNER C3100CN yes EFF test
Color imageRUNNER C3200 yes EFF test
Color imageRUNNER C3200N yes EFF test
Color imageRUNNER C3220 yes EFF test
Color Laser Copier 1150 yes EFF test
Imageclass MF8170C yes EFF test
LBP 2410 unclear faint dots; could be artifacts
Dell
3000CN yes EFF test
3100CN yes EFF test
5100CN yes EFF test
Epson
AcuLaser C900 yes EFF test
AcuLaser C1100 yes EFF test
AcuLaser C1500 yes EFF test
AcuLaser C1900 yes EFF test
AcuLaser C3000 yes EFF test
AcuLaser C4000 yes EFF test
Fuji: see Xerox
Hewlett-Packard
Color LaserJET 1550L yes EFF test
Color LaserJET 2250LN no (??) EFF test
Color LaserJET 2500 yes EFF test
Color LaserJET 2500N yes EFF test
Color LaserJET 2550 yes EFF test
Color LaserJET 2550L yes EFF test
Color LaserJET 2550N yes EFF test
Color LaserJET 2600N yes EFF test
Color LaserJET 2680 yes EFF test
Color LaserJET 2840 yes EFF test
Color LaserJET 3500 yes EFF test
Color LaserJET 3550 yes EFF test
Color LaserJET 3600DN yes EFF test
Color LaserJET 3700 yes EFF test
Color LaserJET 3700DN yes EFF test
Color LaserJET 3700N yes EFF test
Color LaserJET 4500 no EFF test
Color LaserJET 4500DN no EFF test
Color LaserJET 4500N no EFF test
Color LaserJET 4550 no EFF test
Color LaserJET 4550N no EFF test
Color LaserJET 4600 yes EFF test
Color LaserJET 4600DN yes EFF test
Color LaserJET 4600HDN yes EFF test
Color LaserJET 4600N yes EFF test
Color LaserJET 4650 yes EFF test
Color LaserJET 4650DN yes EFF test
Color LaserJET 4650DTN yes EFF test
Color LaserJET 5M no EFF test
Color LaserJET 5100CN yes EFF test
Color LaserJET 5500 yes EFF test
Color LaserJET 5500ATN yes EFF test
Color LaserJET 5500DN yes EFF test
Color LaserJET 5500HDN yes EFF test
Color LaserJET 5550 yes EFF test
Color LaserJET 5550DN yes EFF test
Color LaserJET 5550DTN yes EFF test
Color LaserJET 8500 no EFF test
Color LaserJET 8500DN no EFF test
Color LaserJET 8550 no EFF test
Color LaserJET 8550DN no EFF test
Color LaserJET 8550GN no EFF test
Color LaserJET 9500 yes EFF test
Color LaserJET 9500HDN yes EFF test
Color LaserJET 9500MFP yes EFF test
IBM
Infoprint Color 1454 unclear dithering?
Infoprint Color 1464 PS3 yes dithering?
Konica
(Konica/Minolta)
Bizhub C350 yes EFF test
Colorforce 1501 yes EFF test
Colorforce 8050 yes EFF test
DialtaColor CF 2001 unclear dithering?
DialtaColor CF 2002 unclear dithering?
Ikon CPP500E yes EFF test
Magicolor 2 Desklaser no EFF test
Magicolor 2200 DL yes EFF test
Magicolor 2210 yes EFF test
Magicolor 2300 DL yes EFF test
Magicolor 2300 W yes EFF test
Magicolor 2350 yes EFF test
Magicolor 2350 EN yes EFF test
Magicolor 2400 W yes EFF test
Magicolor 2430 DL yes EFF test
Magicolor 2450 yes EFF test
Magicolor 3100 yes EFF test
Magicolor 3300 yes EFF test
Magicolor 5450 yes EFF test
Magicolor 7300 yes EFF test
Kyocera
FS-C5016N yes EFF test
FS-C5030N yes EFF test
FS-C8008 yes EFF test
Mita KM-C2230 yes EFF test
Lanier
LD238C yes EFF test
LP125CX/LP126CN yes EFF test
Lexmark
C510 yes EFF test
C720 unclear retest
C752 yes EFF test
C752N yes EFF test
C760 yes EFF test
C910 yes EFF test
C912 yes EFF test
Minolta: see Konica
OkiDATA
(Oki)
C5100 no EFF test
C5150 no EFF test
C5150N no EFF test
C5200 no EFF test
C5300 no EFF test
C7200 no EFF test
C7350 no EFF test
C7400 no EFF test
C7400N no EFF test
C9200 no EFF test
C9300 no EFF test
C9400 no EFF test
MIP C5540 no EFF test
OkiLAN 8100E no EFF test
Panasonic
Workio KXCL-500 yes EFF test
Ricoh
(see also Savin)
Aficio 1224C yes EFF test
Aficio 1232C yes EFF test
Aficio CL 2000 yes press report
Aficio CL 3000 yes EFF test
Aficio CL 3000E yes EFF test
Aficio CL 6010 yes EFF test
Aficio CL 7000 yes EFF test
AP 206 yes EFF test
Infotec/Danka ISC 2838 yes EFF test
Samsung
CLP-500 no EFF test
CLP-510 no EFF test
CLP-550 no EFF test
CLP-550N no EFF test
Savin
C3210 yes EFF test
CLP35 yes EFF test
Tektronix: see Xerox
Toshiba
eStudio 210c yes mfr. statement
eStudio 211c yes mfr. statement
eStudio 310c yes mfr. statement
eStudio 311c yes mfr. statement
eStudio 2100c yes mfr. statement
eStudio 3100c yes mfr. statement
eStudio 3511 yes EFF test
FC15 yes mfr. statement
FC15i yes mfr. statement
FC22 yes mfr. statement
FC22i yes mfr. statement
FC25P yes mfr. statement
FC25Pi yes mfr. statement
FC70 yes mfr. statement
Xerox
(Tektronix)
DocuColor 12 yes EFF test
DocuColor 40 yes EFF test
DocuColor 1521 yes EFF test
DocuColor 1632 yes EFF test
DocuColor 2000 yes mfr. statement
DocuColor 2045 yes EFF test
DocuColor 2240 yes EFF test
DocuColor 3535 yes EFF test
DocuColor 6060 yes EFF test/mfr. statement
Phaser 560 no EFF test
Phaser 740 no EFF test
Phaser 750 (Z750V) no EFF test
Phaser 750P no EFF test
Phaser 790 yes EFF test
Phaser 850DP no EFF test
Phaser 860DP no EFF test
Phaser 1235 no EFF test
Phaser 6100 no EFF test
Phaser 6200 no EFF test
Phaser 6200DP no EFF test
Phaser 6250DP no EFF test
Phaser 6350DP no EFF test
Phaser 7300DN no EFF test
Phaser 7300DT no EFF test
Phaser 7700 no EFF test
Phaser 7750DN no EFF test
Phaser 8200DP no EFF test
Phaser 8200DX no EFF test
Phaser 8400 no dithering?
Phaser 8400B unclear dithering?
Phaser 8400DP unclear dithering?
Phaser 8400DX unclear dithering?
Phaser 8400N unclear dithering?
Phaser 8440DP unclear dithering?
Phaser 8550 no EFF test
Phaser 8550DP no EFF test
WorkCentre M24 yes EFF test
WorkCentre Pro (all models) yes mfr. statement
MIT Group Starts Campaign to Stop Printer Companies From Spying On You
july07its actually brailleManufacturers of color, laser printers quietly cooperated with the Secret Service to print nearly invisible tracking codes on every color page printed through laser printers individuals buy, ostensibly as a way to track down forgeries.The Computing Counter Culture Group at MIT Media Labs now wants laser printer owners to start asking hard questions of the manufacturers. And they say that one person who contacted his printer manufacturer got a visit a few days later from Secret Service agents who wanted to know why that person hated freedom.