"It's been posited by researchers that tiny discrepancies in the spacing between words or even the kerning of letters could be used to encode information."

I know some DTP types that this technique would drive them crazy. They spend so much time adjusting the leading/kerning to get the text appear in the layout they way they want. Having that thrown out the window by the printer would absolutely drive them insane. For science, I want to try this out now. It would be awesome to do it as an April Fools joke.