> I don't think I could reasonably expect a person from a journalism/liberal arts degree educational and work experience background to identify steganography.

> I don't think I could reasonably expect a person from a journalism/liberal arts degree educational and work experience background to identify steganography. I agree with nearly everything you said, except this. As others have noted, this sort of document tracing has been deployed and well-known for a long time. I would expect investigative journalists working the NatSec beat to have read a bit of other NetSec investigative journalism, and mention of things like this come up fairly regularly. Not to mention, contact with people like security researchers, EFF staff, etc. will all tend to expose you to information like this - it is part of the paranoid air people who discuss this stuff breathe. Also, a bit of tradecraft is just part of an investigative journalist's job. If I recall correctly, the Intercept people weren't accused (by anyone serious) of intentionally outing her, just of being dangerously incompetent to collaborate with.