Speaking on behalf of the Bestofmedia Network and the moderator team, I can say unequivocally that no such "spy" feature exists.
Even if it did, by some strange coincidence of weird programming on a list of features no one has or would ever request, the staff and moderators are way too busy to indulge in voyeuristic post-snooping. It is challenge enough to ensure proper moderation for what *is* said rather than worrying about what users are *thinking* about saying.