If I need to publish something and have it remain completely anonymous, convert it to ASCII TEXT. That is one of the few formats I understand well enough to be CERTAIN that it is free of metadata.
Now all I have to worry about is how I can anonymously publish it, text style analysis, and how to include diagrams without resorting to ASCII drawings.
This is something you will hear from a lot of places, often from people who never were early adopters of neither mail, sms or skype etc.
The reason I made the comment is because it rubbed me the wrong way to cite 13-year-old girl talk as prototypical gibberish. Are 13-year-old girls generally excitable and potentially annoying? Yes. Do they talk in gibberish as a matter of course? No, that's a thoughtless sexist trope.
And I'll place a blind bet that they text faster than you.
Still think an average hn-er should be able to type faster and more correct on a normal keyboard than the average 13yo, regardless of gender.
I suspect that the actual writing style apart from the markup would provide some clues.
https://www.youtube.com/watch?v=C9SgAOcCm0I
One of the methods they mentioned is machine translation, but they found that it wasn't terribly useful. It's a really neat talk and I highly recommend it. They also wrote some software to anonymize texts (Anonymouth) and their stylometry software (JStylo) is also freely available:
http://events.ccc.de/congress/2011/Fahrplan/events/4781.en.h...