Eugene Leitl wrote:

How safe are nyms from text fingerprints, and be it only word frequency analysis? I have no idea how good the state of the art is, but I wouldn't be risking it for anything production-quality.

Not safe at all, even the unclassified programs are getting better all the time. Check the archives for some interesting past discussion--and if you feel like tinkering around yourself, there's a ton of free software you can download here: http://www.content-analysis.de/software.html Hope that helps! ~Faustine.