In usual researcher style, I promised students complete anonymity in this project. However, the texts they produced are on the web for the world to see. In fact this proved to be one of the more popular aspects of the project: the unusual ability to write material that people other than the prof and the other students might actually read. Therefore, there's not much point in anonymizing people and pretending that readers can't infer in about five seconds which student wrote which quotation from the transcripts.
That observation is trivial compared to the larger issue of not only making students' texts public, but also of moving them to my server to prevent their being extinguished when students' accounts expire. This not only affords students a humble bit of immortality--it also removes from them the opportunity to edit or delete their texts in future. This is the ultimate in textual appropriation.
I have no answer to this.