This was the goal of The Underhanded C Contest in 2008.

http://www.underhanded-c.org/_page_id_17.html

Random thought: using serifs to encode additional bits with a Reed-Solomon would allow for, say, one bit per letter (either we use the serif or the sans-serif version). Assuming latin characters, it would allow for t/2 = 1/16 (6,25%) of the original text - a bit lower if we consider that letters like "o" do not have serifs, somewhat higher if we remove easily-guessable words like "the", "an" and so on.

That's a good idea, I might do a quick Show HN about that.

If that's the case, I think the easiest thing to do would be to transcribe the document and include annotations inline about where content was omitted.

e.g. Go from "XXXX people connected with.." to "[REDACTED] people connected with". So long as it's noted that redaction happened and one doesn't have the source document to glean things from, that would probably be sufficient to block the things the author of this article is doing.

What I'm wondering, though, is if this is permissible. Being able to see how much of a document was redacted gives us some important context:

1. We know we're looking at the "original" report. This might not be the case with an approved transcription of some sort. 2. It's easy for a layman to get a sense of how much information is being withheld.

Knowing what and how much was redacted seems like it's pretty important for maintaining trust and transparency with an organization that has legitimate reasons to withhold some amount of information.

At that point just leak it anonymously somehow. If you do something this cute everyone will know the person doing the reacting effectively leaked it intentionally. Why not just take a picture, strip the metadata, and pass it to a trusted journalist?

You could use steganography to store the redacted parts.

Wouldn't that change the non-redacted parts of the document? Or would there be a cover page with a story about a boy and his dog on every FOIA request?