Such people would be able to deny searching for such terms, I don't see this as posing any more problems than the history dumps. Thinking further though, it would be possible to tie a search to an IP address or User when a page is created with the search term (as it is highly likely if there was only one search that it was this user who did it)
I think the biggest issue is that people expect their search queries to be private. When the word got out that search log might become available we got a couple of angry remarks like "we didn't sign up for this", and "even google doesn't do it". Some form of statistics would probably be fine with our users, but the cut-off numbers would need to be high enough so that people no longer feel it is "their query"..
r.