Doug WebbMar 2, 2020

Today I learned that many/most color laser printers layer an array of yellow microdots on top of documents 🔬

This Machine Identification Code https://en.wikipedia.org/wiki/Machine_Identification_Code encodes a print date and a serial number unique to the machine. It only became public knowledge in 2004, ~20 year after deployment 😑

The Technical University of Dresden released a tool 2 years ago to layer on _even more dots_ to render the MIC unreadable and aid whistleblowers publishing https://github.com/dfd-tud/deda ✊

Machine Identification Code - Wikipedia

Show threadJoachimMar 4, 2020
@douginamug That is how whistleblower Reality Winner was identified and arrested.
https://en.wikipedia.org/wiki/Reality_Winner#Intelligence_report_leak,_arrest,_potential_role_of_The_Intercept_in_her_arrest_and_sentencing
Reality Winner - Wikipedia

Show threadDoug WebbMar 4, 2020
@joachim damn. And to think I had no idea I was producing these dots myself til last week!
Show threadjums
@douginamug @joachim you produce much more than you think you do, that surveillance captitalism 101 :)
Mar 4, 2020 at 1:00pmWeb
Show threadkrugarMar 4, 2020
@jums @douginamug @joachim
There's a US FOIA answer with a list of manufacturers that include these, and it's ...basically all of them ;) since we're on this topic, if you want to add dots to your document for fun, use these: https://en.wikipedia.org/wiki/EURion_constellation :P
EURion constellation - Wikipedia

Show threadresist1984Mar 15, 2020
@krugar @joachim @douginamug @jums there's a lot of fuzziness there. For some printers there is a concrete "yes" to the #trackerdots question, and for others it's up in the air. Obviously ppl should avoid buying a printer that's confirmed compromised. Oki is a good bet. It's non-US, & Oki doesn't have scandals and dirt that most makers have.
Show threadresist1984Mar 15, 2020
@jums @douginamug @joachim @krugar This is where some of my info comes from: https://www.eff.org/pages/list-printers-which-do-or-do-not-display-tracking-dots
List of Printers Which Do or Do Not Display Tracking Dots

Warning (Added 2015) Some of the documents that we previously received through FOIA suggested that all major manufacturers of color laser printers entered a secret agreement with governments to ensure that the output of those printers is forensically traceable. Although we still don't know if this...

Electronic Frontier Foundation