@riking / @Mittineague:
Thanks for your responses. We'll definitely need to make sure our approach is kosher, and ensuring the sensitive data isn't available to the students. We're mostly looking to mine things like text data / user behaviours... not anything personally identifiable, just things that are generally publicly available to anyone who can view our Community.
Good call on the direct user messages, didn't even realize that was in there. This changes things considerably, so we'll proceed with caution before moving forward.
However - any idea why we're getting mixed results for the # of posts?