Some people were horrified when deja.com (since bought by google) started archiving usenet postings and making them searchable on the web. They thought their usenet postings would disappear forever when the posts dropped off the news servers because of age.

More people were horrified when google started indexing pdf, Lotus, Excel, PowerPoint, Word, rtf and other formats. Some companies had put payroll info, etc on the web in those formats, in the belief that no one would know they were there.

I apologize for stating the obvious, but even if there is a robots.txt exclusion for the forums (and the powers-that-be may not want to do this because of the number of people who become new flyertalkers by seeing a forum thread in a google search result), the public can still read these forums. As I write this, 315 people have viewed this thread alone. Nobody knows who they are.