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 ✊
@douginamug That is how whistleblower Reality Winner was identified and arrested.
@joachim damn. And to think I had no idea I was producing these dots myself til last week!
@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