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

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

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 github.com/dfd-tud/deda ✊

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@joachim @douginamug It's interesting that the dots were readable on The Intercept's *published version* of the documents, which seems to imply they did a really high quality color scan, no? Who does that? Why wouldn't a newspaper be smart enough to scan (presumably text) docs as a bitonal image where a yellow dot would be assigned white and not black?

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