The real question you should be asking yourself is how hard it is to fake these. If I get hold of someones copies, can I use them as template?
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They were clearly betting on the fact that no one would notice they are there. What scares me is we're just finding this out. How long have criminal organizations and rogue nations known about this and what have they used it for?
https://en.wikipedia.org/wiki/Printer_steganography
There were press articles about it by 2004 (and I think some earlier), we had written the tool that Rob Graham used to decode these scans by 2005, and I gave a number of TV interviews about it during 2005. A small number of manufacturers (maybe worried about European data protection laws) also alluded to the existence of the technology in their user manuals. Some of the people from industry who contacted me also said that this was common knowledge to people in the printing industry since at least the turn of the millennium.
As far as I've seen, this isn't true.
Before today, what was the most likely path to this knowledge? As in one month ago...and how many 26 year olds have occasion to learn themselves the details of printers? Nobody uses printers.
Yes, working in that position it would be more likely, but she still could merely be a corner case when it comes to laser printer dot awareness, even within the IC.