As it looks like, post revisions are public.
Sometimes, a new user (or somebody who did not think long enough) posts code samples that contain real-world data that should probably not have been there in the first place. Like in this question: http://stackoverflow.com/questions/3166873.
Now when the person corrects the mistake and uses harmless data instead, search engines will still happily index the old revision, so somebody might find data through a regular search that was never really intended to be public.
Adding "nofollow" to the links that point to revision pages would prevent that kind of disclosure. So:
- Did I get the facts right (about search engines seeing revisions)?
- Would it make sense to prevent this for protection of the lightheaded (and the third-parties that do not even know that their data has been disclosed)?
- Would it break useful functionality?