Tim May writes:

Imagine what can be done with word and phrase frequency analysis, with examination of punctuation styles (e.g., some people use _this_ for emphasis while others use *this*), and so on. Entropy measures, etc.

I know for sure that Soviet KGB did a lot of work in graphology and kept samples of print of every typewriter there was in the country. <not that it helped them ;) > It might be easy to write a program that would randomly modify spacing, indentations, punctuation styles, spelling, replace words with random synonyms, reorder words in phrases, etc. It can eliminate most of the clues, excluding the concepts. You will have to compromise between the accuracy of the message and its privacy protection, but it is still something... Alexander Chislenko