On Fri, 5 Jun 2009, Jim Redmond wrote:
As several others have mentioned, noindexing won't prevent vandalism, won't prevent mirrors from showing the hidden content, and won't prevent direct visits to the hidden content. Additionally, as I mentioned in a comment on your blog, most BLP-related complaints on OTRS are more concerned with the vandalism itself or with the wiki-nature in general - Google doesn't really enter the picture unless their cache is outdated.
The Google problem usually shows up in situations where it's hard to prove-- prospective employer Googles subject, turns up inaccurate Wikipedia article about subject, rejects subject for job without ever mentioning the Wikipedia article.